Dinosaur, Razorfeather Raptor 2014

Advantage on attacks vs. creature if 1+ unincapacitated attacker ally is within 5 ft. of target.

If the raptor moves at least 20' straight toward a creature and then hits it with Claw attack on the same turn that target must make DC 13 Str save or be knocked prone. If the target is prone the raptor can make one Bladed Feather attack vs. it as a bonus action.