Snuffles
From UnknowableWiki
Snuffles is a nickname of Sirius Black's. While on the run, he asks Harry Potter, Ron Weasley and Hermione Granger to call him by this name when talking about him inside Hogwarts (GF27). They comply (GF27, GF28, GF29, OP17, OP18, OP29).
Sirius refers to his Animagus form as Snuffles when volunteering to accompany Harry to a Ministry disciplinary hearing on August 12, 1995 (OP6).
Harry addresses a letter to Snuffles, and warns Hedwig in private that the owl post is to be delivered to Sirius (OP14).

