This is from the Friends of old Gerber portfolio.
Dave organized the publication to raise money for Steve
Gerber. Steve was in a lawsuit with Marvel at the time
about the ownership of the character Howard the Duck,
depicted here together with Cerebus, fighting windmills.
Dave drew this panel and inked two more, none of which
I've ever seen in print. Actually I've never seen the
portfolio on the market, just this plate, so it has
probably been reprinted later on.