Merle Colby Allin Jr. (born April 9, 1955)[1] is an American bass guitarist.

[2] Allin played electric bass for three groups that featured GG Allin: Malpractice, The AIDS Brigade and the third version of The Murder Junkies; he currently continues the latter, his brother's final backing band, with original drummer Donald ("Dino Sex") Sachs, and several younger members.

[4] Allin was also bass player in late 70s Boston punk group Thrills (a.k.a.

[6] He subsequently joined the band Cheater Slicks, and played bass guitar on their debut album On Your Knees.

Outside of his work as a musician, Allin is a noted collector of serial killer memorabilia and was featured in three installments of Soft White Underbelly.