|“||I'm going to kill you, Nyan Cat!||”|
Tac Nayn is the evil, waffle-bodied twin of Nyan Cat, a singing, space-traveling cat with a Pop-Tart body, found in a popular YouTube video.
One day Nyan Cat was flying through space minding its own business, when suddenly Tac Nayn blew Nyan Cat right out of space with a laser. Nyan Cat fell down to Earth, so Tac followed to find Nyan and see if he actually was dead, After a long search, Tac found him ― but only for a minute, because Nyan, not in the least hurt, immediately zoomed off.
The pursuit now continues right through the middle of the Fusion war. Whenever Tac finds Nyan, he tries to catch him, but Nyan is too fast for him, as well as for the fusion monsters, causing the Fusions to chase Tac.
Whenever Tac needs a break from chasing Nyan (and from being beaten up by fusion monsters), he heads to Wave Island, on which there are none. Players can generally find him there for that reason.