The title of this article is a conjectural. Though the topic is found within The Simpsons universe, a proper name is not available.
The Past Horrors couch gag is the fourth couch gag of Season 11.
The family members (mostly) appear as they have in previous Halloween episodes: Homer is a jack-in-the-box (from THOH II), Bart is a mutant fly (from THOH VIII), Marge is a witch (also from THOH VIII), and Maggie is an alien (from THOH IX); Lisa, an ax murder victim (the only one not based on a previous episode), comments on the lackluster Halloween special hosted by Kang and Kodos ("What do aliens have to do with Halloween?"). Maggie yells in Kang's voice, "Silence!" and vaporizes Lisa with her ray-gun, before she puts her pacifier back on.