Elliot Ingber joined The Mothers early in 1966, shortly before they signed with Verve.
Recorded on the Boy Wonder I Love You sessions.
Ingber plays guitar on:
You Can't Do That On Stage Anymore Vol. 5
The Lost Episodes
He can be seen in the Zappa movies Uncle Meat and Video From Hell.
After leaving The Mothers in 1967 he formed Fraternity Of Man.
Joined Captain Beefheart in the early 1970's performing as Winged Eel Fingerling.
From the "biographical trivia" section on the Freak Out! (1966) album:
... Elliot digs the blues. He has a big dimple in his chin. We made him grow beard to cover it up. He just got out of the Army. Lucky for the Army.