For a deadly wombo combo have a megalania and a microraptor, the microraptor stuns a player while knocking them off their mount and the megalania gives them rabies

Infects attacked survivors with rabies which will slowly kill them unless cured. Rabies is contagious and passed to other survivors in close proximity. So unleash a plague and then exit swiftly.

You can breed them while they are mounted on the wall. I found it's the best way to breed them because they don't move around. But be carefully their egg goes to the other side of the wall so make sure you have access to both sides.

Press spacebar (PC) to enter literal all-terrain mode.

Seriously, the thing can walk on ceilings with it!