Tragg and the Sky Gods published by Gold Key in the 70's were one of my Science Fantasy jams growing up. According to the Wiki entry; "Tragg and the Sky Gods was a comic-book title published by Gold Key Comics in the mid-1970s. The series was created by writer Donald F. Glut and artist Jesse Santos. Later, artist Dan Spiegle would work on the title."
Tragg is a tough hombre of a caveman & a 6th level fighter proficiant with any stone age weapon. He gains a +2 in hand to hand combat. And seldom really flappable in the face of some insane prehistoric enemies. His mate Lorn is a 4th level fighter & also proficiant with a wide variety of prehistoric weaponry.
No. Encountered: 1
Alignment: Neutral good
Movement: 30 (40 swim)
Armour Class: 8
Hit Dice: 3+3
Attack Rate: melee or by 1/1 (weapon)
Damage: 1d6, 1d6, or (per weapon + 1)
Saving Throw: 14
Experience Points: 90
Treasure Class: I
Trag & his mate Lorn could easily make the transition over into Hyperborea. There are a number of other dimension gates within the prehistoric era that Trag & his tribe operate out of. Trag for all of his savagery is actually a decent tactican especially when it comes to the safety of himself, his mate, & his tribe.