Based on an IRC joke, where someone linked this video as Saucy Spitfire-
's Doctor Adorable because: labcoat!
All stuff is © its creators (Dexter's Lab to CN, My Little Pony to Hasbro, Doctor Adorable to GiantMosquito, art to me, etc)
EDIT: Oh hey, it got into the Drawfriend without me sending it! Equestria Daily, Drawfriend 415, #26 on PB: [link]