I’ve seen them spawn in ark genesis oceans

I had one steal 40 mejoberries and now I have a pet pegomastax named ugly rat because it tamed on the spot

A wild pegomastax has stolen 24 rotten meat. "Meh"
A wild pegomastax has stolen 4 narcotics. "Uhm... meh"
A wild pegomastax has stolen mastercraft longneck rifle. "GIVE IT BACK YOU LITTLE SHIT!"

It will steal your cryopods ! Once lost a level 80 argy to a pegomastics