Battle Bears -1
Tentacleese first appears in BB-1 as a pink Huggable that is seen playing in spilt nuclear waste. Because of the exposure, it rapidly mutates into what appears to be part Huggable, part octopus. What is now dubbed as 'Tentacleese' attacks Riggs and a fight ensues.
Tentacleese attacks by squirting milk out of its udder, spawning small Green Huggables, and hitting the player with its fallen tentacles. Riggs must kill it by shooting its body until it dies. The player is also able to shoot off its tentacles to make it less dangerous, but this tactic requires timing and accuracy as the small Green Huggables will kill them if they stay in one place too long. As a result, the player has to shoot while moving. The tentacles will also cling back onto the columns if Riggs does not shoot down all four within 30 seconds. When defeated, Riggs or Oliver can play against it in the Boss Trials.
There is an alternate way of defeating Tentacleese. If the players shoots its udder enough times, it will actually fall off and run around. Tentacleese itself will die, but the player must shoot the fallen udder a number of times to actually defeat the boss.
Battle Bears Fortress
Tentacleese is the boss of the second world, the Canyon world. It can destroy player's turrets with its creeping tentacles. The tentacles first appear on the first and fifth rows, followed by the second and fourth until finally all five rows have tentacles creeping up on them. These tentacles can shield advancing Huggables from attack and only recede when they are shot at. It can also shoot an unknown projectile, which randomly destroys the player's turrets.
The Udder Chaos is the name of the udder of Tentacleese. After shooting the udder for long enough, Tentacleese will die, but the udder will fall off and run around. It will shoot milk everywhere, and occasionally it will spray a smoke screen, similar to that produced by squids. The player has to shoot it continuously for an extended amount of time before it finally dies. After it dies, a cutscene plays where Riggs calls the udder "Udder Chaos."