Late at night, a young girl named Roberta rushes outside to untie a panicking goat that quickly rushes into the house. Her mother scolds her for being out of bed, and Roberta voices her worries that the chupacabra is after the goats. Her mother assures her that there is no chupacabra, but is interrupted by a growl. A shadow jumps out of a nearby tree, and Roberta and her mother run inside, attempting to block the door with a table, but the figure breaks through. They hide, awaiting their fate, when the sun rises, and the figure disappears. Roberta and her mother step outside to survey the damage. Roberta's mother shouts, "The chupacabra is real!"
Jackie and Jade are in Mexico, exploring a step pyramid. Jade complains that she is bored, until they accidently wake a sleeping jaguar. The jaguar chases them out of the pyramid, and, as they run, Jackie receives a call for El Toro. El Toro asks Jackie for help with translating some ancient tablets that may reveal a way to rid them of the goat-eater, el chupacabra. Jackie agrees, and Jade jokingly tells Jackie he should get voicemail.
Jackie and Jade meet with El Toro and Paco. Jade appears upset that Paco is there, but Paco simply states that it is good to see her and kisses her cheek. El Toro tells Jackie they need to prepare to battle the Chupacabra. Jackie says he only came to translate the tablets, but El Toro says there is no time and that "the beast attacks by dark of night." In the back of the van, Jade and Paco begin to argue about who is strongest, Jackie or El Toro.
The group go to the farm at the beginning of the episode, where Roberta describes the chupacabra. Jade tells Paco "Yep, sounds like a chimichanga to me," but Jackie is skepitcal, saying it is more likely a coyote when the goats begin to panic. The chupacabra appears and Jackie rushes everyone inside, sans himself and El Toro. Jackie arms himself with a rake, and El Toro rushes the beast. When the beast easily throws El Toro, Jackie abandons his rake and picks up a broken support beam, however the chupacabra throws him as well, turning its attention to the house where a goat is bleating.
Inside, Paco and Jade are barricading the door. Paco tells Jade he will protect her. Jade hears something and pushes him away from a window just before the chupacabra breaks through it and comes inside. Everyone hides in a back bedroom. Roberta's mother says that there is no other door, and Paco suggests simply giving the chupacabra the goat, but Jade threatens him.
Jackie jumps inside through the broken window, and El Toro breaks through the barricaded door. There is a short fight, and the chupacabra throws Jackie and El Toro through a wall. Jackie and El Toro again charge the chupacabra, but Jackie hurts his leg. El Toro tackles the beast and holds it down as the sun rises, and it disappears. Paco praises El Toro for defeating the beast, but El Toro says it was not him but the sunlight. Paco and Jade resume their hero argument, but El Toro interrupts, saying that they must celebrate their victory.
In town, El Toro notices that the goats are afraid and reveals that the chupacabra scratched him and that he fears he has been infected by the beast. Jackie asks to see the tablets El Toro wanted him to translate.
Jackie begins to translate. The sun begins to set, and El Toro, appearing to be in pain, asks Jackie to translate faster. El Toro transforms into the chupacabra and chases Jackie. Jackie runs into a group of people and tries to warn them away, but they simply comment on El Toro's "nice costume" until he roars and frightens them away. Jade and Paco see Jackie running. Jade is confused, and Paco pulls her out of the way as El Toro charges by. Paco comments that her recognizes El Toro's mask. El Toro corners a group of people, but Jackie distracts him with a goat-shaped pinata. During a brief skirmish, Jackie accidently removes El Toro's mask, and is forced to explain to Paco that El Toro is no longer the bull, but "El Toro-cabra" but reveals that he already called for help.
Uncle arrives and says he needs one more ingredient to cure El Toro, a powder made from capsicum, and to get it they must visit the wise elder atop el Picaho del Diablo, the Mountain of the Devil.
On their way to the mountain, the group is attacked by El Toro. El Toro, spotting the mask in his hand, attacks Paco. Jackie quickly makes a bo staff from two tent poles and distracts him, and Jade pushes Paco out to the way. Jackie realizes that El Toro is after the mask and tells Paco to drop it, but he refuses. Paco leads El Toro to a cave and Jackie pushes him inside just as the sum rises. El Toro turns back into a human and tries to go outside, but realizes that the sun still hurts him. The group chains El Toro inside the cave to prevent him from leaving, even after nightfall, until they return with the finished antidote.
Jackie, Jade, Uncle, and Paco make it to the top of el Picaho del Diablo and, upon hearing that El Toro has been turned into a chupacabra, the elder gives them the capicum. Down the mountain, El Toro transforms and escapes. The group finds him chasing a herd of goats, and Jackie gives him the antidote. Paco returns El Toro's mask to him. Uncle tells El Toro not to go swimming for half an hour, and the group walks away, Jade and Paco, again, resuming their hero argument.