Alternate Universe: In which everyone has goatees. The comic is also "mirrored" (hoHO), that is to say, the standard comic image is flipped left to right before dialogue (and goatees) are added.
Alt Text: Used for comments or additional punchlines. The strip titles (only found on the archive page and feed) and "contact" links for each strip serve similar purposes.
Also, T-Rex once says the words "Sandwichtastic" and "Sandwichocracy" in one sentence. God then hints that the entire universe was created just to see if those words could be in the same sentence.
God: YOU WOULDN'T THINK IT WAS A BIT OF A LET DOWN AT THE END THEN HUH
Chekhov's Gun: Explained in this strip of the "Literary Technique Comics" series. May involve Pop-Tarts.
Choose Your Own Adventure: "CYOA" that amusingly features a But Thou Must. A later guest strip by Andrew Hussie features T-Rex attempting to do an animated strip version of a CYOA, with Dromiceiominus and Utahraptor discussing with him about the problems with handling a CYOA in said format. It falls apart in the fifth panel, where T-Rex and Utahraptor end up carrying their conversation through the panel shifts. In case you want to read the whole thing at your own pace, here you go. Click the swf(image) after clicking the link and then use the left and right arrow keys (on your keyboard) to navigate.
Continuity Nod: After espousing the benefits of having a truly gender-neutral third person singular pronoun (and deciding that 'thon' sounded coolest) T-Rex uses it in a blink-and-you'll-miss-it way later on referring to gender-neutral babies.
One intrepid fan actually prepared and ate the recipe invented by T-Rex, which involves frying up equal parts of ground beef and ice cream, throwing in some eggs and salt and then serving it in a bathtub with a cash garnish. This concoction was described as "astonishingly edible".
One strip mentioned a steel-drum-and-theremin version of the Cheers theme song. A fan recorded it soon after.
The Ditz: T-Rex is a pretty smart dude! However, his boundless enthusiasm for anything that gets in his head leaves him with no self-awareness, self-restraint, sensibilities, or respect for laws of physics.
About Interacting Socially: This can be tricky! You want to be friendly, but you don't want to come on too strong. My best advice is to carefully observe others, and to relax!
A God Am I: T-Rex swaps places with God for about 2 minutes, until God forces them to swap back after realizing much to his disgust that T-Rex's mouth tastes like T-Rex spit.
And just when T-Rex had figured out the controls too >:|
Great Way To Go: When something is sad—like death—but also awesome—like an arrow managing to hit something not even the size of a quarter when dropped randomly from a plane—it is sawesome.
He Who Must Not Be Seen: Every member of the cast aside from T-rex, Utahraptor, and Dromiceiomimus, to varying degrees.
A Hell of a Time: In Hell you can play video games and do whatever you want, but you have to sing songs with all the lyrics replaced by "party".
How We Got Here: Parodied in this strip, which begins with T-Rex discovering that everybody died. It then flashes back three weeks earlier, where we find T-Rex... discussing about charging MP3 players with his friends. The last panel ends with a message appologising that they went so far back that the events that led to everybody dying haven't started yet, ending with "LISTEN, THANK YOU FOR READING MY COMIC TODAY".
Lampshade Hanging (every once in a while, a joke about the parameters of the comic, eg here or this one lampshading the lampshading.) This was explained/parodied in this strip, also from the "Literary Techniques Comics" series.
Painting The Medium: God talks in BOLD ALL CAPS. The Devil meanwhile speaks in BIG RED LETTERS, and the raccoons and cephalopods ARE UNNERVINGLY ITALICISED.
Remix Comic: Technically, every strip after the first one; fan-made Remix Comics of it are, of course, also common.
Retconning The Wiki: It suggests that we solve this problem on Wikipedia by only vandalizing the article about chickens, because "dudes already know about chickens."
sometimes i imagine my life where i write the same comics i've been writing, but instead of publishing them online i put them in a big stack, or, you know, wallpaper my house with them and never invite anyone over. hah! WHO IS THE CRAZY ONE NOW
Satan: One of the odder incarnations of the Adversary in fiction, he's a nerd obsessed with Video Games whose voice comes in from the bottom of the panel. Like God, he talks in all-caps without punctuation.
Toronto's politicians and tourism board will look up and shout, "Boo hoo hoo we can't increase tourism and we've never even tried calling ourselves 'Omega City, Where It's Always Two For One Tacos', tell us what to do, Ryan" and I'll look down and whisper, "No."
Straight Gay: Utahraptor (and by extension... T-Rex? The very first story arc involved the two having sex ... somehow). It's not a big deal, and is seldom mentioned. T-Rex is probably bisexual; he and Dromiceiomimus have also had dinosaur sex. Then again, T-Rex doesn't remember the event, and questions if it really ever happened. (Non-consensual dinosaur sex?) We're pretty sure that time travel was involved. Word Of God confirms that Utahraptor is gay but "doesn't go on about it that much because he has interests outside of being gay?".
T-Rex: "I am a new man, cats and kittens!" (title: FUN FACT: i do some translating in the comics. t-rex originally said "i am a new tyrannosauroid, protomammals and juvenile protomammals!")