@soix is correct, Skip Spence was The Airplane’s drummer on their first album. He took off for Mexico with a coupla chicks without telling the group, and was mia for a few scheduled shows. They fired him, and he ended up playing rhythm guitar and singing in Moby Grape.
I read somewhere that before joined MG he was briefly in the San Jose band The Chocolate Watchband, but I saw every local show they played and I never saw him onstage with them. Throughout the 70’s, 80’s, and 90’s you would occasionally see Skip wandering the streets of downtown San Jose (he was living there in a halfway house), bumming cigarettes and asking for spare change. Like Syd Barrett, Brian Wilson, and Peter Green, a victim of LSD.