Tasty is an achievement that can only be won with the Necroa Virus DLC.
How to get this achievement?
Evolve Autophagia, Polyphagia, and Cannibalism, at least. However, this combo is very rare, so players may have to try multiple times to acquire it. It's possible, although quite unlikely, that this achievement will be unlocked in an attempt to unlock the Not Another Zombie Game achievement.