Connor Lacey's Super Adventures of Regular Show: A Bunch of Fully-Growned Geese is the 9th YIFM/Cartoon Network crossover made by Connor Lacey. It will appear on YouTube in the near future.
The episode begins with Mordecai, Rigby and Pops making a sandwich at the park's lake. After they make the sandwich, a gang of vicious Geese show up to terrorize the groundskeepers and the people surrounding them, reducing Pops to tears, and ruining their lunch. Mordecai and Rigby tell Benson about the situation, but after Rigby talks back to him about the job of ridding the park of the geese, the duo are chased out of the house as he throws a fit.
Mordecai and Rigby attempt to get rid of the geese by using blankets and geese repellent, but both of these methods fail and make the geese angrier.
The two ask Skips for advice, who tells them that they're on their own after hearing that the problem is geese related. However, he does tell them that ducks are the natural enemies of geese, and they should contact any duck friends they might have. Mordecai calls up the Baby Ducks, who tells him to use lasers.
Returning back to the lake with laser pointers, three of the geese fly away. Rigby notices that one of the geese is missing, who discovers that they are the source of the lasers. The geese drag the two out of the bush and beat them up, before ripping out a tree and prepare to finish them off, when the baby ducks arrive and save them.
The baby ducks try telling the geese to leave, but the eyes of the geese give off a red glow and one of them talks (much to Mordecai and Rigby's sheer surprise). The geese refuse to leave, saying that they have taken over the lake and gotten rid of the humans and anything else that isn't a goose. The leader of the geese then says that if the baby ducks want it, they have to come and battle them for it. The baby ducks accept. The geese then transform into a giant four-headed goose robot, while the ducks transform into Eagle Man. They battle each other. After a while of battling, the ducks get extremely hurt. They then tell Mordecai and Rigby to fist pump. Their Eagle Man form upgrades and then they defeat the geese.
Benson arrives, enraged at the amount of destruction in the park. He scolds Mordecai, Rigby, and the baby ducks for the mess they made. The Mother Duck then arrives, very annoyed and angry at Benson, for not appreciating the fact that Mordecai, Rigby and the baby ducks saved the park and possibly the world, when they defeated the geese and for scolding at her children. Benson begrudgingly apologizes to them, and leaves sad and gloomy. Mordecai, Rigby, Mother Duck and the baby ducks celebrate their victory. The episode ends with pictures of them hanging out in different places.
- The Legion of Cartoon Heroes and The Reform Squad will guest star in this film.
- In this film Antauri and Yubel's Combiner ability has increased.