According to the preview copy, this is a one shot issue by Brian Butler and Brook Allen. According to the inside cover its by KC Green and Alison Strejlau, but I guess that was before the fill-in became necessary. Either way, it looks fine.

Regular Show #5(A)
Writter: K.C. Green
Art by Allison Strejlau
SC, 32pgs, FC, SRP: $3.99
Diamond Code: APR13 0957

Mordecai and Rigby are once again finding themselves in a situation that they will naturally make worse! Get ready for this special one shot issue, written by Brian Butler, art by Brook Allen (A HOME FOR MR. EASTER) and with incentive covers cool enough to hang in your rec room!