Despite being primarily Charlie Brown’s pet beagle, Snoopy lives a very active fantasy life in which he has personified several alter-egos, each one of them properly costumed and/or attired. Among these are: Joe Cool, the Easter Beagle, the WW I Flying Ace, Flashbeagle, and many others.
Woodstock:
Snoopy befriends a bird named Woodstock, who speaks in birdchatter, and they have many adventures throughout the Peanuts comic strips.