Bunny Ears Elder God: All the characters have their own problems... Cthulhoo eats humans, the Shoggies have little intelligence, 'Zatoth is just as stupid, Yogzozot has a bad temper, and Dagoon bashes stuff with a stone pillar, to name a few.
Catch Phrase: "Fhtagn!" for Cthulhoo, "soooo cooooooool" for the Shoggies.
Engrish: The author is French, and occasionally makes some very odd grammatical errors. The worst of these are usually corrected.
Evil Is Not a Toy: As usual, invoking Cthulhoo is an incredibly bad idea. Of course, invoking the other gods can be just as bad, and summoning them all... well...
Grotesque Cute: This is still the Cthulhu Mythos, and the gore factor actually goes up compared to Lovecraft's stories (since here you're more likely to see someone dismembered than be told they suffered unspeakable horrors).
I'm a Humanitarian: Cthulhoo's most defining trait. In fact, the whole point of his invocation phrase is to let him know where to find lunch.
Lovecraft Lite: Fridge Brilliance style. The element of Cosmic Horror Story remain unchanged. Cultists still kill people for sacrification, reading text from Tome of Eldritch Lore... uh, RPGs sourcebook is enough to get you devoured and mythos beings are still extremely dangerous. However, they are bunch of goofs and human can be awfully annoying to them.
Running Gag: Lots of them. Cthulhoo's gluttony, the Shoggies' stupidity, cultists getting eaten, etc. Not to mention people summoning Cthulhoo by accident every couple of strips.
Spell My Name with an S: The names used for a lot of the Mythos characters are spellings Lovecraft never used; this is to avoid the ongoing copyright controversy involving his work.
Sufficiently Advanced Alien: One of the justifications Cthulhu uses for eating his own followers—he's more like a wild animal than a god anyways.
Tongue on the Flagpole: Apparently, a pile of shoggoth(s?) grew some tongues for the specific purpose of sticking them onto a glacier when teleported to the Antarctic by the Elder Things in this comic.