Mordecai

Mordecai (Also known as Captain Mordecai; The Regular Avenger) is the most Regular dude of all the peeps. He has a friend named Rigby which is a raccoon, you can find him in the Regular Dimension with the other gang.

Mordecai is good friends with Phineas99

Regular Dimension
When Rookie opened a new dimension for April Fools Party 2011. He was the Regular Dimension, but soon, decided to keep it a secret and closed the dimension.

Soon, when Phineas99 had the idea to create a Dimension Expedition, he opened the Regular Dimension, and he saw Mordecai, Rigby, Pops, and many other people from Regular Show. Mordecai and Rigby decided to leave their dimension and get a new job at the Coffee Shop, however, Mordecai and Rigby will still visit their dimension. Mordecai soon became good friend with Phineas99