Antrax is a character from the 1987 cartoon, originating from the toy line. He is said to be "Krang's executioner from Dimension X", which makes him an alien rather than another mutant.
There are roughly one-sh*t billion tropes so PLEASE look through them before adding one. Otherwise add what you like. ADDITION: PLEASE read through the trope description provided before submitting something. It's not a huge deal but too often people submit characters that don't fit just because they misinterpreted the title...
