Brygmophyseter skull.

Brygmophyseter might look like a normal Sperm Whale, but this whale had a nasty attitude and T-rex sized teeth. This whale lived during the Miocene in Japan. Brygmophyseter also lived alongside Megalodon and, in a pod, could rip a full-grown Megalodon to pieces. Brygmophyseter also ate dolphins, seals, and squid.