Updated in 2017:
I mean, the below still applies I guess, but I have to add that these were the drawings of a teenager aged 14-17 or so. There are many jokes and incidents that I know now are unacceptable and in poor taste. A lot of the characterisations are bad as well (many are homophobic) and please know that I do not think those are funny today.
Frequent use of mild language (ie, damn, crap, bitch), infrequent use of strong language (ie shit, bastard), very very rare uses of very strong language (ie fuck).
Refrences only. Usually mild.
So far there's been one incident of "Jesus-humour". I try not to make any
refrences to religion, but that one time it was suggested by someone else and I though
"hey, why not".
Phrases like "oh my god!" are frequently used.
Two characters are homosexual (not with eachother though), enough said.
There isn't really anything else that's a controversial matter in the comic.
The comic is drawn badly. On purpose.