Angry Birds in Epic Battle Fantasy 4 is a combination of the game Angry Birds and the game Epic Battle Fantasy 4. The birds are basically taking the place of 4 heroes to defeat a god named Godcat, which consists of a white, blue, and holy cat named the Creator, and a black, red, and dark cat named the Destroyer, and together, they are referred to as Godcat.
Red Bird, Yellow Bird, and Black Bird enter King Pig's castle where the eggs are, and King Pig seems ready to open up a portal. It sucks in Red Bird and Black Bird. Yellow Bird, however, tries to escape, but the portal becomes stronger and sucks HIM in. Meanwhile, at the Temple of Godcat, the 4 heroes, Anna, Matt, Natalie, and Lance are fighting Godcat. The Creator tells the Destroyer to destroy the 4, because he is the Destroyer. Anna protests that they can't do so, but the Destroyer doesn't listen, and starts with Lance. Next up is Natalie, Matt, and finally Anna. Red Bird finds himself at Greenwood Village. Black Bird finds himself at Ashwood Forest. Yellow Bird finds himself with Matt at Greenwood Village. Matt is amazed, so he tells Yellow Bird to find his friends and together destroy Godcat. Matt eventually goes on a journey to find his friends. Red Bird keeps worrying about the eggs, so he freaks out all around the village. Black Bird, at Ashwood Forest, finds an ash on his fuse, annoyed at the fact that he is going to explode. Red Bird finds a sword that says, "Go to my place. -Godcat". Then, Red Bird thinks of a plan.
Ashwood Forest - Red Bird and Yellow Bird find Black Bird, obviously, in this place which used to be a nice forest, but then turned into an ashy rotten forest. The three birds eventually find the neat part of the forest and find the Mighty Oak, the boss of Ashwood Forest.
Crystal Caverns - The three birds find Ice Bird in this wonderful cave of crystals. Ice Bird seems to be collecting crystal so that he can be able to make them cold. After venturing through the cave, they find the boss of Crystal Caverns, the Crystal Golem.
Waste Disposal Plant - The flock finds White Bird here, upset that he got the job to take out all the waste, but he hates waste, and likes nature better. Eventually, the flock finds a way to make White Bird quit this stupid job. Eventually, they find a mecha named Praetorian, the boss of the Waste Disposal Plant.
Lankyroot Jungle - In this all-natural jungle, the flock finds Orange Bird, who is collecting cocoa beans to craft his very own chocolate. Eventually, they find the Rafflesia, the boss of Lankyroot Jungle. However, this jungle is owned by White Bird.
Goldenbrick Resort - In this calm place near the coast, the flock finds the Blues, at the beach. The Blues invite the birds to play with them for a while. Eventually, the Blues are informed about Godcat, so they enter the last place.
Temple of Godcat - In this temple in the sky, the flock finds Purple Bird and the Mighty Eagle, and they tell the rest of the flock what the Godcat is up to. Eventually, they fight the Godcat and save the world.