When The Sneak enters Tammany Hall, he sneakily costumes as a human (well, not quite). This costumed The Sneak is The Dapper Swindler.
The Dapper Swindler appears on a wanted poster in The Ballad Of The Sneak and The Sneak's nose and fangs still show. The poster reads:

WANTED: "The Dapper Swindler"
Known in the North-West Territories As: The Sneak

Complete Filmography

Ballad of the Sneak (Debut)