Dr. Killbot, also known as Señor Killbot, is the supporting antagonist in the Phineas and Ferb special, Phineas and Ferb Saves Summer. He is a robot with a human brain and can only speak improper Spanish.
He is one of the members of L.O.V.E.M.U.F.F.I.N.. When Heinz Doofenshmirtz announced that he has succeeded in moving the Earth away from the Sun to early autumn with his latest -inator, Killbot and the other villains are very impressed by this. At that moment, Aloyse von Roddenstein decides to lead L.O.V.E.M.U.F.F.I.N. to take over the world. After the villains capture almost all of O.W.C.A.'s agents (except for Perry the Platypus), they head over to Danville City Hall, where Rodney introduces Killbot to the people in case any of the world's extorters speak Spanish, since he doesn't want to leave anyone out.
Killbot was present when Rodney contacted the world leaders about the progress of their plan, and when the world leaders informed that the pretzels demand is the only one that hasn't been met, Killbot watches as Rodney sets his -inizor (which is just ten times the size and strength of Doof's -inator) to send the Earth to perpetual winter, delighted to see that the world is now under L.O.V.E.M.U.F.F.I.N.'s grasp.
During the climax of the episode, Killbot is seen trapping the arriving Monty Monogram, Carl Karl, and Perry (thanks to the help from Dr. Diminutive and another unnamed evil scientist), but they are interrupted by the arriving Major Monogram, who manages to get a street rat to free all the captured agents. This results another fight between the agents and villains, which happens to be the same one earlier in a ballroom during the beginning of the special. When this was pointed out by Dr. Diminutive, Killbot and the other villains all decide to flee away from the scene for good.
- Dr. Killbot only speaks in Spanish in the English dub. Yet he spoke in a broken English in the Spanish dub. He's also referred to as Mr. Killbot in the Spanish dub.
- Dr. Killbot is referred to as Señor which means either Mister or Doctor in Spanish.