The earliest iterations of the Kangaroo were created from M3 and M5 Stuart light tanks to serve as artillery tractors in North Africa campaign in circumstances where Universal Carriers were unavailable.

Lieutenant-General Guy Simonds, commander of II Canadian Corps, devised Kangaroos as a field-expedient alternative to purpose-built APCs.

[a] The Priests were "defrocked" at the Advanced Workshop Depot under the codename "Kangeroo", removing their 105 mm guns and ammunition stowage, and separating the driver's compartment from the rest of the vehicle.

[1] When the 3rd Canadian Infantry Division was re-equipped with towed Ordnance QF 25-pounder gun-howitzers in late July, the rest of their self-propelled tracked vehicles were stripped of their 105 mm guns and converted to Kangaroos.

Kangaroos in general were supposed to carry 8 to 12 soldiers, though similar to the practice of troops riding on tanks, it was more common to simply cram as many as could fit without being at risk of falling off.

Accordingly, climbing rungs were soon added as a field modification that also simplified loading the carrying compartment with ammunition, food and other supplies to troops under fire.