mutant
noun
°Something which has mutated, which has one or more new characteristics from a mutation.
"Your plaid fish are mutants."
°Someone or something that seems strange, abnormal, or bizarre.
"I think your brother is a mutant; he’s so weird!"
adjective
°That has undergone mutation.
"Your mutant fish are dying."
°Strange, abnormal, or bizarre.
"Your mutant brother just growled at me again!"