St. Mordecai is a blue jay. He is the best pal of Rigby, he is more responsible and more clever. He usually doesn't take Rigby's way round the bend because he does better stuff and won't lose his bodiless conscienceness. He has perversions over a bird called Margaret and does annoying farts towards Rigby during Halloween night and to Benson when he first worked with him in a gas station shop. He once gave dodgy candy to Benson and accepted it. It contained Cilit Bang and Benson turned into a gross blob.
He once worked in a gas station shop with Benson, he wasn't his boss but back then he really hated him due to his rude jokes, dodgy candy and annoying farts. He was fired for giving his boss a pizza with a flat Furby baked inside. After meeting Rigby, they started to get slacky and met Benson again as a park keeper so the two worked with him instead.
How he met Rigby
Mordecai met Rigby around the block in a cardboard box next to the ShameHobo. the ShameHobo taught him how to play video shames and when he met Mordecai, he got into his personality and became friends, the ShameHobo gave him the Nintendo UnEntertainment System and some shames. From then they decided to job hunt.