Dog Costumes: Butterick 5117- Sizes XS, S, M, L, From 2007
Get your pup all dressed up! A jester with belled collar & hat; a spooky bat collar with a bat hat; a pumpkin; a flower; a wizard and a devil...with an adorable tail.
Looks like 29 pattern pieces. Sizes are XS (11"), S (16"), M (21") and L (26"). They don't actually say, but I would assume this is the distance from the base of the neck to the base of the tail.