T.K. Lives! is the first mission in a chain involving Zombie T.K. Baha. The mission is available from the southwestern area in Hallow's End, and is initiated by interacting with the prosthetic limb on the porch of his Hallow's End shack.
Find T.K. Baha
"T.K. Baha's prosthetic leg! T.K. Baha must be nearby. Find him!"
As soon as you accept the mission the front door opens. Go inside to T.K. and turn it in.
" T.K. Baha lives ... sort of. The poor guy has been turned into a zombie and all he can talk about is brains. Maybe you can ease his pain."
None of the brains gathered before starting this quest line count for the quest. Thus, it's best to enter this quest line as early as possible.
T.K. still appears in the base Borderlands game outside of Fyrestone, either sitting in his chair or hanging dead from his ceiling fan depending on the status of the Is T.K. OK? quest.
Oddly enough, if you go back to Fyrestone, TK is still sitting in his chair, hanging from the ceiling fan, or both.
He is the only non-hostile zombie in the game.
Despite the background, T.K. does not need to be dead to begin this questline.
T.K.'s rambling list of ways to cook and prepare brains is a reference to the movie Forrest Gump when Forrest's Army buddy, Bubba, lists all of the ways you can prepare shrimp.
When T.K. says "boil 'em, mash 'em, stick 'em in a stew" he's referencing Samwise Gamgee's (Lord of the Rings: The Two Towers) speech on the many ways to cook potatoes.