Pachycephalosaurus 

the act of head butting a chick in the mouth during sex

# 2 : i was with this guy last night - he called me a freak and gave me a Pachycephalosaurus . busted my lip right open.

# 1 : not cool man , not cool.

Pachycephalosaurus by islamorada in 2:45 minutes December 24, 2010

Pachycephalosaurus 

An ornithischian dinosaur from the Late Cretaceous period (70-66 million years ago) known for it's domed skull. Additionally the largest member of the family Pachycephalosauridae.

"The dinosaur Pachycephalosaurus is thought to have used it's domed head in combat with other members of it's species."

Pachycephalosaurus by ankylosaurusfangirl January 14, 2024