My nicknames in alphabetical order:
Doug E Fresh
Doug Funny
Dougie Big Nuts
Drain Bamage
Handsy
Lancaster
Mr. Doug
Mr. P
Pahoehoe
Paul
Paul Hida
Pow
Powie
Pow-Pow
Rat Boy
Rat Man
Uncle Doug
(From the comments and additional names I remembered afterwards)
Poodle
Grandes Boules
Doug Doggie Dougg
Velveeta
Egotistical Bastard
Radio Boy
If you can think of any others, please let me know.