Robbinson Lantz Crosby (August 4, 1959 – June 6, 2002) was an American guitarist who was a member of glam metal band Ratt, earning several platinum albums in the US in the 1980s.

He was the son of Harry W. Crosby, a science schoolteacher at La Jolla High and an author of books about California history.

[11] The same year he also recorded a live demo with the band Aircraft, which also featured Rob Lamothe, later in Riverdogs with Dio/Whitesnake/Def Leppard guitarist Vivian Campbell.

However, the move to the Los Angeles area provided Mac Meda with access to a vibrant club scene, which they soon became a part of, even playing the famed Troubadour (West Hollywood, California) on May 7, 1981.

Crosby's solos were blues-based, as he drew inspiration from Jimi Hendrix, which gave Ratt melodic flavors.

Feeling "overshadowed" by DeMartini, Crosby began "self-medicating with drugs and alcohol," which led to a crippling heroin addiction.

In a June 1999 interview for a Ratt episode of VH1's Behind the Music, Crosby talked about how drug addiction and his HIV status changed his life.

Crosby also attempted various musical projects, first (post-Ratt) re-uniting with Perry McCarty, Krys Baratto, Dino Guerrero and Mark Lewis as an updated version of Secret Service, a moniker used by McCarty and Crosby previously for their pre-Ratt San Diego band.

Although his death was reported to be from complications from AIDS, he actually died of a heroin overdose (although he had also previously tested positive for HIV).