Mr. Smiley is the hidden main antagonist of Scooby-Doo! and the Monster of Mexico.
He decided to ruin a business by scaring away all their customers by having his girlfriend, Charlene, dressed as El Chupacabra. He already has one of his theme parks in the U.S., but wanted to open up his "Mr. Smiley's Latin Adventure" theme park on the Oteros' property. He even made a fake ghost hologram of the late Senor Otero, lying the people in the cemetery that were celebrating The Day Of The Dead, that if the Oteros sell their land, the curse of El Chupacabra will go away forever and that Charlene will be returned "unharmed." Fred takes a look at Luis' medallion that Charlene gave him, it was actually a tracking device. There was a red button on the back of the medallion. Fred pushes the button, making Scooby and Chiquita following the noise made by the tracking device. They stumble upon a nearby tomb, learning that a man in a skeleton costume is controlling the hologram of the late Senor Otero with some video game-like controls. Scooby and Chiquita began barking at the skeleton costumed man to get everyone's attention. The skeleton costumed man tells the two dogs to be quiet, but to no avail they continued barking.