The Wolf tank was the symbol of Chinese tank design reaching maturity, but the first reason for its limited production was its "son" — the 25-ton tank "Panda," armed with a 76.2mm/L40 tank gun — arriving as a "premature birth." And this "son" was "secretly born" by someone else.

The Wolf's design bureau was Northern Heavy Industries' Second Design Bureau, located at the Guangzhou branch. Tianjin headquarters, having lost the tank design competition to the branch, regarded this as a humiliation beyond bearing. After its "Flying Squirrel" tank lost yet another bidding round to the Wolf, chief designer Gao Bupang decided to skip the 20-ton standard entirely and go straight to a 25-ton class tank.

At this time the Wolf had already entered mass production, and the Armored Forces Committee had just issued the "Universal Chassis" standard specification, introducing the concept of commonized vehicle components for armored forces. Gao Bupang — who believed he'd read the committee members' minds (really Chen Ke's mind) — deliberately selected Wolf tank components wherever possible during the design. When the prototype emerged, 50% of its chassis parts were sourced from the Wolf.

Having correctly intuited Chen Ke's "big vehicle, big gun" thinking, Gao Bupang "connived" to present his newly tested tank to Chen Ke during one of the Chairman's visits to the Northern Heavy Industries Tianjin Manufacturing Bureau — under the guise of a "Wolf improved variant." The 76mm big-bore main gun, the visibly larger-than-Wolf physique — this instantly hit Chen Ke's sweet spot.

The subsequent performance demonstration in front of Chen Ke did not disappoint. Regarding this scene, the on-site recorder captured the following exchange:

Chen Ke: "This tank is a Wolf improved variant?"

Gao Bupang (wiping cold sweat): "Yes! See, these five road wheels are the same as the Wolf's..."

Chen Ke: "Looking at this physique, this tank isn't light, is it?"

Gao Bupang: "24 tons empty, over 25 tons combat-loaded. A bit over spec, yes."

Chen Ke: "I don't know much about tank design, but jumping from a 47mm gun to 76mm — the turret, the chassis — they'd all need redesigning. This is actually a new tank, isn't it?"

Gao Bupang: "Ah..." (wiping cold sweat incessantly)

Chen Ke: "Where did you get the design budget?"

Gao Bupang (putting on a long-suffering expression): "After we lost to the southern branch in the last bidding round, the comrades in our bureau were deeply unconvinced. So I took the lead in scrounging everywhere — we scraped together every last pot and pan to make this happen. It may be a new tank, but half its parts are interchangeable with the Wolf."

Chen Ke wore a pensive expression, then uttered a phrase that later generations never quite understood: "It's a bit like the J-10."

Two days later, Gao Bupang received orders: the Armored Forces Committee directed him to send the new tank to the testing grounds in Inner Mongolia. After a round of trials, the new tank's firepower, mobility, and protection were all highly satisfactory. To demonstrate confidence in his tank, Gao Bupang personally drove the new vehicle, sitting inside while ordering another Wolf tank to fire its 47mm gun at him from 600 meters. The results showed that not a single round could penetrate the new tank's frontal armor. Rumors later circulated that before the test, Gao Bupang had secretly welded an extra 40mm-thick armor plate in the driver's compartment. Naturally, Gao Bupang himself vehemently denied this.

The new tank's excellent performance upon its 1938 debut meant the Wolf — barely into mass production and deployment — was immediately rendered "obsolete." After reviewing the Armored Forces Committee's evaluation report, Chen Ke's pen stroke sealed the Wolf's fate: cease all Wolf production once existing orders were filled.

However, out of a complex mixture of admiration and censure for the Northern Tianjin Design Bureau's unauthorized initiative, Chen Ke gave the new tank a mischievously amusing name that brought a wry smile: Panda.

The Panda tank's design was subsequently taken by their German collaborators and became the prototype for the famous Panzer IV.

By the end of 1938, the Panda completed all testing, resolved its various design defects, and finished production drawings in January 1939. At the same time, Wolf production ceased entirely. Existing production lines began retooling in preparation for Panda manufacturing.

During the 1939 Southeast Asian war against Britain, in complex mountainous terrain, the newly mass-produced Panda did not shine on the battlefield — the star of that war was the Air Force. The British collapsed at first contact. The few Pandas that saw deployment couldn't even reach the front before fighting ended. The Panda essentially "ran" through the entire campaign without firing a shot.

Although China later developed the Cloud Leopard tank, which boasted more powerful firepower with its 90mm tank gun, it still could not fully replace the Panda's position in the armored forces. Tests revealed that in the southern paddy fields and mountainous terrain, the Cloud Leopard — with a combat weight exceeding 35 tons — had severe mobility problems in hilly terrain. By comparison, the lighter improved Panda D model was far better suited to the hills and valleys of South Asia. Front-line combat reports confirmed the Panda was not obsolete. The outstanding D model, refitted with a long-barreled gun and new engine, approached the Cloud Leopard's performance while consuming less fuel, having superior cross-country capability, better acceleration, and greater mobility. The Panda production line was maintained through the war's end.

The Panda tank had four different variants from A through D. Including its derivative vehicles, total chassis production exceeded 15,000 units.

The A model saw 500 units produced. After the Southeast Asian war, battlefield-revealed problems led to the B model's development. Existing A models were nearly all recalled to factories for B-standard conversion, making surviving A models extremely rare. B model factory-fresh production totaled approximately 3,500 units. Roughly 2,000 B models were provided as aid materials to the Soviet Union and Japan — 1,500 to the Soviet Union and 500 to Japan.

After the Australian landing campaign, to achieve absolute firepower superiority over American-supplied M4 tanks, the more powerful L/50 76mm tank gun was developed, yielding the C model. The C model's origins actually predated Australia: after the Soviet-German war erupted, the Pandas supplied to the Soviets encountered their most significant opponent — their "relative," the Panzer IV, armed with a 75mm/L48 tank gun — and found themselves at a firepower disadvantage. Simultaneously, the Soviets were also lengthening the barrels of their same-caliber 76mm guns. Pandas still in production no longer held any firepower advantage.

The Panda's development was inseparable from German assistance; both nations shared the results. When the German version — the Panzer IV — began mass production, Hitler, out of "Aryan" pride, demanded it carry a more powerful gun than the original Panda. The Germans chose a 75mm bore with a 48-caliber barrel length for their first production batch, whose armor-piercing performance surpassed China's Panda from the very start.

Determined never to lose in the "barrel length" department — and intent on squeezing every last drop of potential from the Panda — the C model, equipped with a 50-caliber 76mm gun, was developed as the tank's definitive firepower variant. With the subsequent development of APDS (Armor-Piercing Discarding Sabot) rounds, the Panda C could match the firepower of the 88mm-armed Tiger tank. However, early APDS rounds had design flaws causing accuracy to plummet beyond 500 meters, a situation not improved until 1944 after the projectile head structure was redesigned. Due to the expensive tungsten used in these rounds, aside from China itself (which possessed abundant tungsten mines), even the Soviet Union — which had received large numbers of Pandas — could not afford to use hardened tungsten-core APDS "gold coin rounds."

Because the Panda and the German Panzer IV were relatives with extremely similar exteriors, friendly fire incidents occurred repeatedly after Pandas were sent to the Soviet Union. To differentiate them, later batches of the C models supplied to the Soviets had a 5mm-thick thin steel armor shroud added around the turret exterior to distinguish them from the Panzer IV. In practice, this modification was discovered to also enhance protection against Panzerfaust-type anti-tank rockets. The design was quickly adopted for the Panda D and Cloud Leopard tanks. The rather tragic irony for the Soviets was that the Germans later copied this Panda design feature for their own late-model Panzer IVs — and China's Pandas in Soviet service still couldn't escape being hit by friendly fire.

The D model underwent large-scale improvements: a new engine, transmission, and gearbox identical to the Cloud Leopard's. Armor was thickened, weight increased to 28 tons. The engine installation layout for both tanks was identical — engines, transmissions, and gearboxes were directly interchangeable, reducing the burden on front-line maintenance units. The D was the Panda's final and most powerful variant, and also the highest-production model.

With engine power increased by 100 horsepower and a dramatically improved power-to-weight ratio, its mobility was outstanding, performing brilliantly even in mountain warfare. Many armored units simply used the D model as a reconnaissance tank.

On Australia's severely water-scarce western front, where supply was difficult, the Panda — with superior acceleration and greater engine power reserves — was better suited than the 34-ton Cloud Leopard for tropical and desert theaters. Its sortie rate was higher, its operational endurance better, and front-line supply requisition priority even exceeded the Cloud Leopard's. In the tropical heat, engines struggled to run at full power, and the Panda's nearly seven-ton weight advantage over the Cloud Leopard made its mobility advantage even more pronounced. Thus on the scorching Indian and Australian fronts, the Panda D's deployment numbers nearly equaled the Cloud Leopard's, with equivalent status and importance.

For long-range armored penetration maneuvers across Australia's vast expanses, the lower fuel consumption of the Panda made it more suited for theater-wide mobility than the Cloud Leopard. Combined with the Panda's consistent performance against its primary adversary — the M4 tank — and overwhelming front-line demand, the Panda could never be taken out of production.

On the frigid Soviet-German front, naturally, the Cloud Leopard outperformed the Panda and received higher evaluations. Overall, both the Cloud Leopard and Panda were outstanding tanks: the former was suited for temperate or subarctic theaters, the latter for tropical, desert, and mountainous environments.

In the wild, the cloud leopard is an agile predator while the panda is ponderous and slow — but in Chairman Chen's Zoo, these two creatures' capabilities were precisely the reverse of their names.

During the Singapore campaign, the Panda's performance was a mere flash in the pan. The real shock to Britain came on the Indian front and from the French campaign on the Western European front. Against the "Chinese Panda's" 76mm/L40 gun and its German brother's 75mm/L48, the armor of British Matilda tanks and French Char tanks was like tissue paper. Meanwhile, the Panda's 60mm armor angled at 60 degrees turned their adversaries' anti-tank guns into laughable "door knockers."

The Panda first faced truly formidable opponents in the British-developed Comet tank and the M4's improved variant, the Firefly, whose ferocious 17-pounder gun could guarantee mutual kills at equal ranges. American M4 tanks in their early variants were at a comprehensive disadvantage. But the mid-war improved M4A3 series onward — with thickened armor and a new 76.2mm tank gun — became worthy adversaries capable of matching the Panda blow for blow.

What truly surpassed the Panda were the British-developed Centurion tank and the American M26 — but by then, the far more powerful Cloud Leopard and Elephant, two new members of "Chairman Chen's Zoo," were already on the front lines to deal with them.

Beyond the tank itself, the Panda chassis spawned numerous derivative vehicles: the "Grizzly" — a self-propelled gun mounting a 155mm heavy howitzer; the "Black Bear" — a tank destroyer with a 90mm tank gun; the "Lynx" — a self-propelled anti-aircraft tank with quad-mounted 20mm guns; the "Flying Bear" — an anti-aircraft tank with twin 37mm AA guns (China's copy of the Bofors gun); the "Fire-Breathing Bear" — a flamethrower variant; turretless battlefield recovery vehicles, bridgelaying vehicles, and more.

There was also one interesting derivative: a light tank developed on the Panda chassis for use as a reconnaissance tank, designated the "Red Panda." Its design thinned the Panda's armor and featured a redesigned, more compact turret. Armed with a new low-pressure 76mm gun, it even swapped the engine for a gasoline motor to reduce noise and improve stealth — a modification that proved controversial within the armored forces. Many tankers argued that gasoline reduced range and increased vulnerability to fire, and the marginal stealth gain wasn't worth the trade-off. Others countered that a light tank spotted by the enemy was dead with one hit regardless — diesel or gasoline made no difference — and low-noise stealth was more important. In response to this debate, rear-area ordnance departments developed a diesel engine power pack that could be swapped in at the front, letting front-line units choose according to their needs.