Doomsday at Bikini Beach (1999)

Three giant Chihuahuas, from outer space, travel towards the Earth to take over the earth. Kyle Lemke, the survivor of their last attack, goes to see a psychiatrist for the trauma he has suffered. The Shrink, who is in league with the Chihuahuas, hypnotizes Kyle to thinking the best thing for him is to go on a vacation. Kyle decides to go to the beach. He gathers up his friends and they head for the beach. Disguised as three girls, the Chihuahuas intercept the boys on the way there and join them for the party. At the beach, the girls shed their disguises and return to their giant Chihuahua forms, and they attack the boys. Traumatized, the boys walk back to the city, where they are safe, for now.