Kronk

Kronks were "monsters" Barbarius took care of before they fought in the Rome Hyp-Arena in an alternate Rome. They originated from the Crab Nebula, but the "killer Kronks" that fought in the Hyp-Arena were trained on Earth. (COMIC: Doctor Who and the Iron Legion)

Jack Harkness once speculated whether they were made into Kronkburgers. (AUDIO: R&J)