Army Dillo is a gargantuan Army that is a boss in the game Donkey Kong 64. He is appointed by King K. Rool to be the Army guardian of not one but two keys to K. Lumsy's cage. In his first fight with Donkey Kong, Dillo is equipped with two large retractable side-mounted fireball cannons, and a metal shell. The battle mainly consists of Army Dillo retreating into his shell and shooting fireballs from his cannons. The only time Donkey Kong is able to injure Army Dillo is when the Army peeks out from under his shell, giving DK a short amount of time to throw a TNT Barrel at Army Dillo. When Army Dillo is hit by the barrel, the explosion throws him into the air and his shell short-circuits, electrocuting Army Dillo in the process. After this, Army Dillo curls up into his shell and rolls around, trying to run over Donkey Kong. A few seconds after this, Army Dillo rolls back to a different position and tries to hit Donkey Kong with fireballs again. This procedure repeats until Army Dillo is hit with a third TNT barrel. When this happens, the short-circuiting of Army Dillo's shell also causes the fireball cannons to be blown off his shell. Seeing this, Army Dillo runs away, leaving the first key to K. Lumsy's cage.
Army Dillo talking to K. Rool After Army Dillo is defeated by Donkey Kong in Jungle Japes, he is cowering in fear while being watched by King K. Rool. Dillo says to K. Rool that Donkey Kong was too quick for him, and that he will "get him next time", most likely referring to their second encounter in Crystal Caves. K. Rool however, is angry at Army Dillo's failure and glares at him. Army Dillo is so frightened by K. Rool's glare that he faints, falling on his back.
Before he faces Donkey Kong for a second time, Dillo is retooled in a Kremling base in Crystal Caves. His weaponry is upgraded with side-mounted rocket boosters, which gives Dillo the ability to perform a shock-wave ground slam. He is also upgraded with a gigantic top-mounted cannon, capable of launching rapid streams of fireballs and homing rockets. In the battle within Crystal Caves, the fight between Army Dillo and DK basically follows the same procedure as their battle in Jungle Japes, only that Army Dillo uses his shock wave attack after he tries to crush Donkey Kong and before he attacks with fireballs again. Also, when Army Dillo's side cannons explode after receiving another TNT barrel to the face, he keeps on fighting, using his shock wave attack again before he reveals his new top-mounted cannon. Army Dillo then hovers in the air and fires fireballs into the ceiling which rain down on DK. When the last fireball falls, Army Dillo lands and fires a missile which homes in on Donkey Kong. Once that explodes, Army Dillo peeks out from under his shell again. This gives Donkey Kong a limited amount of time to hit Army Dillo with another TNT Barrel. When hit, the short-circuiting of Army Dillo's shell causes the shell to start exploding randomly before it completely blows up. Shell-less, weapon-less, and naked, Army Dillo magically flies into the air while spinning. The speed of Army Dillo's spinning increases until Army Dillo disappears, leaving the sixth K. Lumsy Key behind. It is not elaborated what happened to Army Dillo after the rematch.