Twisted Image is a cartoon strip by Ace Backwords. In a style inspired by R. Crumb, it lampoons countercultural stereotypes and documents Backwords' experiences as a homeless resident of San Francisco. The strip has appeared in numerous zines and was featured in The Factsheet Five Zine Reader.
Some Twisted Image comics are available here: http://paranoia.lycaeum.org/stories/comix/back/
Some drug-related Twisted Image comics here: http://www.virtualvenice.info/MiscPages/Ace_on_Drugs/
A collection of Twisted Image comics was published by Loompanics in 1991, but is now out of print.