Initially conceived and created by Capcom to test the game's collision detection, Tofu was given its own minigame, The Tofu Survivor, as a parody of HUNK's The Fourth Survivor. To unlock the Tofu scenario, you must have unlocked The Fourth Survivor, and cleared the Leon A/Claire B storyline 3 times with an A ranking. In the remake, one has to just finish The Fourth Survivor once.
Tofu goes through exactly the same environment that HUNK does, complete with HUNK's cutscene voice. Tofu is armed only with a knife and a few herbs, but it can also take more damage than human characters. In the original game, Tofu will instead change color when it takes damage, going from white to blood red when on danger and dark pink when poisoned. In the remake, Tofu's body will show damage, losing pieces of its body.
Whenever Tofu is attacked, it swears in the Kansai Japanese dialect, and when it is killed, it mutters "farewell" in Japanese. Ironically, things don't end up very well for Tofu, because HUNK is shown eating a part of it aboard the chopper in the ending FMV.
Tofu appears briefly in the "secret mode" in Resident Evil: The Darkside Chronicles. It replaces zombies with Tofu as you fight from the Raccoon Police Station's courtyard to the crashed truck appearing at the beginning of Resident Evil 2 (Zombies and Zombie Dogs are seen chasing down Tofu 'zombies' at one point though). The player character is Claire Redfield armed only with a handgun.
Tofu was supposed to be in Marvel vs. Capcom 3, but did not make the cut.
Tofu can be unofficially used in Resident Evil 3: Nemesis by hacking the game, its files are leftover/ported along with some of its sounds, it might imply that Tofu was originally planned to be playable at some point during the development of the game, other survivors player data are included too, such as Dario and Brad.