Alexander is a dog Theodore adopted in The Alvin Show episode Theodore's Dog.
History[]
Theodore asked Dave if he could have a dog but Dave said no citing they travel too much.
However Theodore secretly adopts a dog from the shelter anyways and hides him in the basement.
Eventually Dave discovered the dog and was angry at Theodore for getting the dog behind his back although Alvin convinces him to bring the dog with them on tour
Trivia[]
He bears a strong resemblance to Clifford the Big Red Dog who would debuted a year after this episode aired