Morg is a reptilian alien prisoner who swaps bodies with Phineas Flynn in an attempt to escape incarceration.
He first appears on Phineas and Ferb's galactic interweb, advertising what seems to be a vacation deal. The boys, along with Isabella, Buford, and Baljeet, agree to the deal and build a machine which they use to swap minds with Morg and his cellmates. It is then they find out this was all a trick and that they have been trapped in prison. Candace soon finds out about the plan and sets off to stop Morg. As the kids get to work on another device to send them back to earth, Candace lures Morg and his teammates back to the mind-swapping machine and finally returns them all to normal. Back in prison, Morg replies to the guard that he's been framed.
Morg is a chameleon-like alien with green scales, wearing a striped prison jumpsuit. After swapping bodies with Phineas, his humanoid body consists of grey skin. His eyes are yellow with slit-like pupils, which can change to the shape of squares when under a spell. He is also known to say "Mmmm" after most of his sentences.
His partners-in-crime also look like amphibians and reptiles, with the exception of one who looks like a fly.