Gorn

The Gorn are a reptilian species of large, powerfully built hunters with scaled skin and a fierce manner. They are strong and dangerous, and their appearance has changed over the years as the franchise has revisited them. Their home territory lies beyond Federation space.
Little is known about their society beyond their willingness to defend territory aggressively and their ruthlessness toward anyone who threatens it. They are shown as meat eaters and as thoroughly territorial, and they have often been presented as an alien threat that cannot easily be reasoned with.
They first appeared in the original series episode Arena, in which Captain Kirk is forced to fight a Gorn captain after the two ships come into conflict, with the Metrons forcing the duel. Kirk ends the fight by sparing his opponent. The Gorn later feature in Strange New Worlds, where they are presented as a far more menacing threat, notably in the attack on the Starfleet colony on Parnassus Beta.