Also, the entire Garden of Edam storyline was dreamed by Jessica.
Alternate Universe / Another Dimension: Two universes other than the main one have appeared - one where black people are discriminated against (which isn't true in the main universe), and one where Dave and Jessica never met.
Blue and Orange Morality: Ecoism (Jessica and Dave's religion) is portrayed as superior to the other religions in the strip (Euphemism and Ecotology), even though all their rules seem just as arbitrary as each other. Ecoists believe in never using water for anything except drinking to avoid damaging the "ecos", Euphemism appears to be similar to Christianity or Judaism (although they believe that Adam is still somewhere on Earth), and Ecotologists also want to save the ecos, but think that they can accomplish this by populating the country of Asia with clones of everyone from the rest of the world. The main Ecotologist even has blue hair to contrast Jessica's orange hair!
When the comic started, the strips continued from each other, but there was no overall plot. As it continued, there were clearer storylines and references to previous strips that tied the whole thing together more. The characters have become more fleshed out and backstory for several countries was revealed. And, for a while, the comic had the main plot of the war between Ireland and the South Pole continuing in the background of other, smaller plots. However, this hasn't made the comic any less insane...
Identical-Looking Asians: Inverted. Not only do the Asian characters look different from each other, each Asian is a clone of each non-Asian person, so Asia is by necessity as diverse as the rest of the world.
Idiot Ball: Some characters' intelligence levels vary by storyline. Also, there's a literal example - a red ball that makes you stupid while you're touching it.
Magic A Is Magic A: Despite the craziness, certain things about the ecos are firmly established, e.g. urine is better than water.
Also, the magic system is coincidentally based on letters - the known types of magic are Qmagic (used by Qwizards, and essentially the same as "normal" magic), Wmagic (used by the Whats in the Portal parody), Emagic (there's only one spell, but its effects are programmable by computer), Rmagic (Summon Magic), Tmagic (affects time), and Ymagic (The Power of Love, used by Cupid).
The Rant: marionic generally portrays himself as being as odd as the comic characters themselves. Usually, the only time the actual real-life production of the strip is mentioned is when a hiatus is being announced.
Series Continuity Error: In an early appearance of Spikeclops, he appears to barely recognise Headmaster Poppington. Later events make it clear that Poppington is Spikeclops' uncle, and Spikeclops' surname is in fact Poppington.
Temporal Paradox: Two objects - Jessica's mask and Dave's fez - literally come from nowhere, having been given to their original owners by people from the future. This causes a "Time Fart", which drains energy from other universes to keep the paradox in place.
Toilet Humour: Given that, in the universe of the comic, urine is the eco-friendly substitute for water, it's not surprising that this happens every now and then.