"The Bogbeast of Boggabah" is the first segment of fiftieth episode of Star vs. the Forces of Evil. It premiered on March 3, 2018 alongside "Total Eclipsa the Moon", and is the first segment of the fifteenth episode in the third season.
Queen Moon is in her study looking over things when Star, once again, bursts in. She tells her mom that they have a crisis on their hands and brings up how Heinous is actually Eclipsa's long lost daughter Meteora. Moon ignores this information, believing that Star is making it up, and scolds her for the party she held at the temple. When Star accuses her of calling Rhombulus to show up and freeze everyone, Moon denies this knowledge and tells Star to get out so that she can finish her work. Star angrily plans on going back in to talk to her, but is stopped by River who tells her that he has another plan for her: to go hunting in the woods. Donning his nature clothes again, River drags Star out into the Forest of Certain Death and devours her shell phone; comically hanging up on Moon while doing so. He introduces her to his ally, a plant wearing expert named Eddie, and reveals their intent to capture the legendary Bogbeast of Boggabah. While Star wants to get it over with, River wants her to follow his directions.
Together, they start off by creating a sauna and sweating away "their fears" as the Bogbeast can apparently smell it. Star callously ends the ritual early by calling on cloudy. Next they have to learn to camouflage with leaves with Star learning the hard way why you should be careful when picking leaves (baby bog dragons live in them). They begin to braid their hair with River braiding Star's hair exceedingly well and Star simply tying River's beard into a knot. Finally, River has Star paint on symbols on his body, but when she does it incorrectly, River tells her that they will have to start over literally from the very first ritual. After going through the four steps again, River checks to see if Star is ready. He determines that she is, but then cracks his back and tells her that she is not. He resolves that they sleep until morning, much to Star's annoyance.
Star is suddenly awoken by a strange sound and in an anger induced state, dons hunting gear and turns her wand into a bow to fight. She runs headfirst into the woods and gets caught and stuck in mud. As the beast draws near, it is revealed to be River awarding Star with a giant headdress. Numerous country Mewmans appear and reveal that the Bogbeast of Boggabah is a title given to those who run impulsively into danger such as Eddie who has been the Bogbeast twice ("I never learn!"). Realizing that she should take things easily, Star decides to stay and party for the night. The next morning, Star returns to the castle covered in mud. She calmly walks up to Moon's door, knocks on it and waits patiently.
- Eden Sher as Star Butterfly
- Rhys Darby as Eddie
- Grey DeLisle as Moon Butterfly
- Alan Tudyk as River Butterfly
- Daron Nefcy as Bog Party Go-er
- This episode and "Total Eclipsa the Moon" take place at the same time.
- This marks the second time a pair of episodes took place at the same time, the first being "Starsitting" and "On the Job".