Dimetrodon Pack

From publisher burb:

These brutal hunters range in size from the smaller 8 foot females to the larger 14 foot males. They are fast sprinters with sharp, spear like teeth. They live in a “pride” structure, with the females doing all the hunting and killing. The males seem to spend their time fighting the larger beasts to protect their prides, or attacking other bulls to take females from their prides.

Small creatures, such as men, do not appear to be seen as a threat to the Bulls, but to the females, any creature near one of their kills is a potential threat.