Slappy first appeared in the third episode of Animaniacs, supposedly as a former Looney Tunes character who has aged because everyone has forgotten her. Because of this, she complains about practically everything, showing only any affection for her young nephew, Skippy Squirrel.
However, despite her complaining and age, Slappy still retains the trigger-happy feeling found in cartoon violence of the 1930's, and uses traditional cartoon cliches like dynamite and anvils to further her jokes, with her sarcasm being her main vehicle of humour.
Slappy has had her fair share of villains on the show, but only a handful have appeared in more than one episode:
- Walter Wolf - A Jewish wolf and the only villain to appear more than three times, and has been criticised by Jewish groups for Walter's constant acts of perjury. Voiced by Frank Welker and later Jess Harnell
- Sid the Squid - A purple squid with a raspy, Daffy Duck-like voice. Appears only twice with speaking lines, and twice in non-speaking cameos. Voiced by Jack Burns
- Beanie the Bison - A slow-minded bison referred to as cerebrally-challenged as a prod at political correctness. Like Sid, he only appeared in two speaking and two non-speaking appearances. Voiced by Avery Schrieber
- Candie Chipmunk - Slappy's spoiled neighbour who pesters Slappy over a soda can, and Slappy performs tit for tat. Possibly voiced by Tress MacNeille
- Doug the Dog - Slappy's first enemy in the series, who only appeared in one episode, and spoke only in grunts and barks. Voiced by Frank Welker
Although Slappy never spun off into her own series, she remains a popular character, and her now-defunct fan club on Yahoo! groups surpassed memberships for all Pinky and the Brain groups, which was until recently the most popular characters on Animaniacs.
Slappy formerly had several articles about her on the satirical wiki site, Uncyclopedia. However, much of the pages were removed from the Uncyclopedia in 2008 following a disagreement between the site moderators and the webpage author. By 2009, no articles about Slappy remained and it appears that all references to her have been removed from the main space of that wiki.
- Slappy Squirrel on Toonopedia