plesiosaur 

noun: ancient dinosaur that came from the ice age. has long neck and scales for skin. also has four fins and an oval body. it propells through the water like a penquin.

person one: woah man! did you see that giant swimming dinosaur?!
person two: i did dude! but that's no dinosaur! it's a plesiosaur! the plesiosaur ogopogo of canada's Lake Okanagan.
person one: you jeefe, shut up.

plesiosaur by sophiemae April 19, 2008

peniosaur 

A prehistoric creature with a large neck large head and soft veiny skin.

"Dude they found a peniosaur bone in my girlfriend's vagina."

peniosaur by Jimmy Higgins February 7, 2008

Plebosaurus-Rex 

These carnivorous creatures lack friends, and make themselves look really good because they also lack self-esteem. These creatures know that they are Plebs and thus they don't change. They feed on the penises of teachers, being massive arse-kissers. If they get detentions then their lives are over, then contemplate suicide.

Some Plebosaurus-Rexes do commit suicide and even the family members will dance on their overly-wide graves. Life is better this way as scientists like Steven Hawking know their threat on the popularity of others while P-Rexes are in a close proximity. Steven, and millions of others like me, want P-Rexes to be extinct from the planet as they are a large danger to humanity.

Chris: Lol, I just owned him on facebook! Look how popular I am, Imaginary Friend!
Spencer: Don't be a Plebosaurus-Rex, Chris!

Chris: Oh no! A detention! Why!! My life is RUINED!! I'm always licking Mr. Lavender's arse!
Lewis: You're such a Plebosaurus-Rex.

Plebosaurus-Rex by LemonyStuff February 23, 2011

peniosaurus rex 

pen·io·saur (pen-nigh-o-s-argh'us, wre-cks-) A very large vagnivorous peninosaur of the Upper Crustaceous Period of North America, characterized by a small neck, large head and scaley skin. A vaginal intruder, the true king of the peniosaurs.

In a prehistoric times, it wasn't all that uncommon for a peniosaurus rex, to destroy a whole flock of ptwatodactyls.

peniosaurus rex by Mattie Macabre December 4, 2007