Gustaf Grefberg (born 18 February 1974) is a Swedish musician. As part of the Amiga scene, he is known under the artist name Lizardking, and much of his production is tracker music. He is or has been a member of the demo groups Alcatraz, The Silents, Razor 1911, The Black Lotus and Triton. He and Joakim Falk invented a musical style called Doskpop and he released various music disks such as "Doskpop The Compilation" or "Memorial Songs 1+2" which feature many tracks in this style. He also took part in projects such as Merregnon and the Symphonic Game Music Concert-series in Leipzig, Germany.
In 1994, he released a compact cassette, Mindlitter, in cooperation with Martin Wall. His songs are on side A and Martin's on side B. They were in person selling the tapes at the Assembly '94 demo party.
He also has composed the score of several Starbreeze Studios video games, including Enclave, Justice, Knights of the Temple, The Chronicles of Riddick: Escape from Butcher Bay, Magus Dawn, The Darkness and Brothers: A Tale of Two Sons.