Dr. Apu Nahasapeemapetilon, Ph.D. Jr. is a recurring character from The Simpsons who appears in "The Problem with a Poo", with the whole episode being a reference to the 2017 documentary film, The Problem with Apu, which focused on the controversies surrounding Apu being a racial Indian stereotype.
Background
After Mr. Hankey gets sent away from South Park, he moves to Springfield, meeting the characters of the town from The Simpsons, with Apu happily greeting him.
Appearance
Apu appears in the art style made to resemble that of The Simpsons, he is an Indian man with dark gray hair, and a small thin mustache, contrary to his Simpsons appearance, he wears a blue collared shirt as opposed to a green one, bright brown pants instead of bright peach ones, and brown shoes instead of black shoes
