Hercules is Herry Monster's monster doll. He has been featured with Herry in "Guys and Dolls", "A Song for Two", "Moonshine", "Monster Lullaby", and "Late Night on Sesame Street" with Conan O'Brien. Hercules was also featured in the street story of Episode 3793 when Herry slept over at Gabi's house.
Herry is not the only monster on Sesame Street who owns a doll. Telly Monster's doll Freddy and Zoe's doll Mimi have also made multiple appearances, as has Elmo's doll Baby David. Big Bird has a teddy bear named Radar.
Herry also has a teddy bear seen in "Good Morning, Morning" and "I Think That It Is Wonderful." In Episode 1261, he has a doll named Elizabeth. In the 1984 book My Doll Is Lost!, Herry has another doll that is very special to him.