Gladys is a character from The Grim Adventures of Billy and Mandy. In the show, she is the mother of Billy. She is a hot-headed, short-tempered woman, who has to tolerance for to idiocy of her son and husband. In Evil Con Carne, she made a cameo in the episode "Company Halt".
For more information about Gladys, visit her page on The Grim Adventures of Billy and Mandy Wiki.