El Chupacabra or Chupacabra (Spanish pronunciation: from chupar "to suck" and cabra "goat", literally "goat sucker") is a legendary cryptid rumored to inhabit parts of the Americas. People believe that a Chupacabra is a vicious creature that takes away a farmer's livestock, in the middle of the night.
One Chupacabra is Agent CH of the OWCA. When Phineas, Ferb, Buford, and Baljeet captured him in New Mexico, Major Monogram contacted Agent P to rescue him. Agent P used Doofenshmirtz's switchinator to make Buford and Agent CH switch places, causing Buford to be in the trap, rather than he. Agent P then gave him Phineas and Ferb's Cupra Copter to fly back to New Mexico ("La Candace-Cabra").
El Chupacabra is never fully seen. It is only partially seen.