Sassy
From Super-wiki
A mashup pairing name for Sam/Castiel which originated in Mishaland, and is largely confined to Sassy_OTP - community for all things Sam/Castiel which delights in Crack, but also features fanart and fanfiction dedicated to stories about the pair.
In comparison with some of the very serious nature of some Dean/Castiel or Sam/Dean shippers, "Sassy" is generally treated irreverantly. Some would refer to it as a Crack pairing, although serious fanfiction does feature the taller Wincehster with the shorter Angel.
The chibi-esque art of nursethalia become particularly associated with the pairing, particularly the comic My Tall Friend, Sam.