Anuboos are one of the many enemies Mario and Luigi faced during the events of Mario & Luigi: Superstar Saga. Mario and Luigi confronted them in Teehee Valley after visiting Little Fungitown. Anuboos are black in color, except for their bright red eyes. They shoot out laser beams at the Mario Bros. To dodge an attack, Mario or Luigi must look at the shape an Anuboo transforms into (either Mario or Luigi) then Jump.
Anuboos are named after Anubis, an Egyptian god in which the species resembles, as well as Boos, because of their ghost-like characteristics and abilities. the word 'Boo' in the name can also be derived from the exclamation "Boo!", which connects to it's shifty nature.
Trivia
Anuboo was the inspiration for making Lucario in Poke'mon Diamond and Pearl