"Monster Bash" is the forty-eighth episode of Star vs. the Forces of Evil. It premiered on November 16, 2017, and is the thirteenth episode in the third season.
All the youth of Mewni gather at the ancient Monster Temple to celebrate a new era of Monsters and Mewmans living together in peace, until guests start disappearing!
- Eden Sher as Star Butterfly
- Adam McArthur as Marco Diaz
- Amy Sedaris as Mina Loveberry
- Jessica Walter as Miss Heinous
- Rider Strong as Tom Lucitor
- Jenny Slate as Pony Head
- Kevin Michael Richardson as Rhombulus
- Dana Davis as Kelly
- This episode marks the third season's mid-season finale.
- This is the sixth half hour-long episode in the series, following "St. Olga's Reform School for Wayward Princesses", "Storm the Castle", "Bon Bon the Birthday Clown", "Face the Music", and "Starcrushed".
- Miss Heinous is revealed to be Meteora Butterfly, the Mewman/monster hybrid daughter of Queen Eclipsa and her monster husband.