I'll quote from a discussion on TMP if you don't mind, to save my typing fingers. Somebody over there asked me the same thing:
"As a large part of the matter was Whites vs. Natives we used "In the Heart of Africa" with improvised Tommy-Gun and gas bomb rules, plus a new agility stat for jumping and such, and "hero-saves" for the more important characters.
But bolted on to the end of that was the "Monster Turn" which was pretty much of my own devising. After all the humans have done their stuff the various monster factions dice for iniative and get their go.
The little raptor pack just had a move+attack action. The larger things like Joe and the Big Lizard had three actions per turn (plus one more if Joe used his rage). Joe's options are listed in the report, but I didn't include the various success chances.
The raptors took damage just like humans (i.e. one hit and they're dead) but the big'uns were divided into hit locations with multiple hit points.
Joe's Locations were:
1) L.Leg (4 Hits)
2) R.Leg (4 Hits)
3) L.Arm (4 Hits)
4) R.Arm (4 Hits)
5) Torso (7 Hits)
6) Head (4 Hits)
Losing all hits to a leg meant that from then on Joe could only use one movement action a turn. Losing both legs would immobilise him. An arm being lost would render that arm useless (which happened during the game) and prevent such things as grapples which required two hands.
Loss of all Torso or Head hits would kill the beast (which also happened).
The Big Lizard was similar, but with different hit locations and different amounts of hit points."