The below mutants cannot be bred and are unable to upgrade with Stars.

Most of them can only be bought in the Shop.

Some of them can be obtained through Mutant Reactor as a bonus, or Challenge Hall by exchange with 180 Challenge Token.

Note that the term itself is not known to be officially called other than the name of icon image being icon_captainpeace.png and is called for Mutants Genetic Gladiators Wiki community for ease of identifying them.