Gender Bender: Evangelyne and Amalia as well as a few extras during the BrÔkmarian Gobbowl arc, thanks to a magic potion. Unusually, all of them are strictly female-to-male gender benders. Justified since women aren't allowed to even watch Gobbowl matches, let alone participate, in BrÔkmar. The vendors make a killing selling the potions to female sport fans.
Hand or Object Underwear: In season 2 episode 11, the gender-bent Fanservice Extra trying to sneak in the stadium covers her chest with an arm when the potion stops having effect. Later, the same thing happens to a topless Amalia, who grabs a gobbowl shield to hide herself.
Hold Up Your Score: Sadlygrove in episode 4, when he's judging the beauty... ahem, ugly pageant.
Hold Your Hippogriffs: For any Earth-based expression using an animal, it is replaced with a species from the world of Wakfu — though the name used is always close enough to keep the meaning readily understandable. And it's not just animals: the first spoken line in the entire series is roughly, "What the bwork?"
A minor one in episode 24. For a little while it looks like the Sadidas might be able to defeat Nox's minions before they can construct a portal to bring in his giant clockwork-spider doom-fortress. Unfortunately it's all a distraction. The horde of minions aren't even building a portal, they're just there to keep the Sadidas occupied while one of Nox's other minions mind-controls a group of Sadidas into building a portal for him (working them to death in the process). The good guys don't realize this until it activates.
Far, far worse in the finale, when Yugo, Adama´, and Nox travel 20 minutes back in time. For a brief moment Yugo thinks that they might be able to prevent Sadlygrove's death, only to discover that they fell a few minutes short.
In season 1 episode 8, Evangelyne scolds Sadlygrove for his bad table manners... just before starting wolfing down herself.
Then in episode 10 she calms Amalia down after finding out the boys have been playing with her Doll. Amalia then argues how she would feel if the guys were playing with her bow. Cut to the guys doing just that, and now Amalia is stopping Eva from killing them.
I Am Not Shazam: In-universe example. The names of the races and the gods that they follow are often used interchangeably. For example, an Enutrof's Fingers (a follower of the god Enutrof), is often just called "an Enutrof".
I Am Who?: Yugo finding out he is the last of the Eliatropes until Qilby appears. Also him being their reborn former king.
Iconic Outfit: The Eliatrope hat which there are a lot of variations upon, but it always has the "ears" and very often the "tail" with the tuft at the end.
The Igor: Igor, who speaks with a strong Eastern-European accent, clearly evokes this. He's not a hunchback, however, but a huge Shushu mirror.
I Warned You: In season 2 episode 5, Sadlygrove tries to warn Yugo, Amalia and Evangelyne of the dangers of the Dragon-Pig's lair, as he's the only one with experience in Dungeon Crawling. They pay him no heed, used to ignoring the Idiot Hero... until the three are struck with a Baleful Polymorph.