After inviting the Diazes on a trip to Mewni as a last minute anniversary present, Star and Marco must save them from a many-headed serpent.
Star is bored out of her mind talking to her parents through the mirror. As River explains that he is going to give a speech about proper throne posture, Moon spots Star's dimensional scissors and reminds her that she is not allowed to leave Earth. Star covers by explaining they are regular scissors and her parents finally hang up. Marco bursts into her room to explain that he is giving a gift to his parents for their anniversary, but Star is disappointed as she did not get anything adding that she wants to because they are "cool", something which confuses Marco. He gives them matching fanny packs, which he had apparently gotten them last year, but he adds that they are upgraded. In a moment of desperation, Star announces that for their anniversary, she will be taking them to Mewni which they excitedly agree to.
They all arrive with Star dissuading the Diazes from going to her castle and suggesting they take in the rest of the kingdom. However, Star spots River buying a spear and panics. Marco suggests that she take dual credit for the fanny packs, but Star insists they continue because they are enjoying the sights. She takes them to the Forest of Certain Death with Star and Marco trying to make sure that they do not get killed. After narrowly avoiding mishaps, Star spots River in the forest and she and Marco try searching for the Diazes. They enter a cave and see their clothes and items lying around as well as a giant seven headed dragon.
Star and Marco take on the dragon and get the idea to tie its heads in a knot which they successfully do so. River suddenly shows up, in primal gear, and cuts the dragon's stomach open, releasing some peasants, but the Diazes are nowhere to be found. They realize that they have been enjoying a hot tub bath in the cave waters this whole time, much to their relief. As Star is being lectured by River, she wonders what he was doing there instead of attending the lecture. He admits that he made it up and that he just wanted to get away from his kingly duties. Realizing that she got her monster fighting from him, Star and River make up and promise not to tell Moon about the day's events.
- Eden Sher as Star Butterfly
- Adam McArthur as Marco Diaz
- Artt Butler as Mr. Diaz
- Nia Vardalos as Mrs. Diaz
- Alan Tudyk as River Butterfly
- Grey DeLisle as Moon Butterfly
- The scene where the salesman flashes his cape open in front of the Diazes is similar to a scene from the film Hercules, where Hercules, Phil and Pegasus meet a sundial salesman who flashes his cape open, offering them a sundial.
- Star makes a visiting return to Mewni for the first time after being sent away in "Star Comes to Earth".
- It is revealed in this episode that River Butterfly likes to fight monsters.
- May 3, 2015 (Canada)
- May 14, 2015 (United Kingdom and Ireland)
- July 30, 2015 (Germany)
- August 10, 2015 (Australia)
- September 6, 2015 (Israel)
- October 9, 2015 (Turkey)
- October 23, 2015 (Poland)
- November 5, 2015 (Spain)
- December 6, 2015 (Southeast Asia)
- January 29, 2016 (Japan)