After Ord makes a wish on his baby tooth at the end of "To Fly with Dragons," he has a fully grown adult tooth where the old tooth was about three seconds later.
After Ord comments on how things like stars are good things to see at night in "The Forest of Darkness", his left fang turns blue for a couple of frames.
In "The Forest of Darkness", after Ord suggests that a light would make him feel better, and the camera pans out to show the whole gang, Zak's leg (or what we can see of it, anyway) is purple.
Ord states in "The Forest of Darkness" that all of the dragons wear dragon badges, but in "Cassie, the Green-Eyed Dragon," Finn, Cassie's younger brother, is not wearing a dragon badge.
When Ord wishes his friends to Kingdom Come, they hadn't yet learned Monsieur Marmadune's name, but Emmy calls him by his name.
When the dragonfrog stands on its hands in the "Shake Your Dragon Tail" segment, the dragonrooster does the same thing, but appears to be hovering since it is not standing on any limbs while upside-down.
In the beginning of "Shake Your Dragon Tail," Cassie's reflection has its mouth open when the "real" Cassie's mouth is closed.
A few times in "To Kingdom Come", Mr. Marmadune acts as if his key is incredibly heavy for him, lifting it with both hands, but other times, he is able to lift the key past shoulder level using only one hand.
In this episode, Ord displays no fear of bugs, but later on in the episode "Don't Bug Me," he's majorly afraid of them.
In "Knot a Problem", after Max says that it's not fair that he can't tie a knot, Zak, Wheezie, and Ord appear to be magically standing about three inches in the air even though they aren't moving their wings.
In "Knot a Problem", Max's balloon has a smiley face on it at the end of the episode, but not at the beginning.
Ord acts in this episode as if he doesn't know that Max can't fly, but he should because Max and Emmy said it in the premiere episode, "To Fly With Dragons."
In "Ord's Unhappy Birthday", Emmy and Max thought Ord was Cassie, though they should have known it was Ord based on Ord's blue tail.
We see the treehouse in this episode, yet later on in Episode #109, Emmy's Dream House, we see the gang building the treehouse. Oops!
Ord's noticeably upset throughout the entire episode, yet nobody seems to really pay attention. Chalk it up to their excitement over the surprise party.
This is the only episode in which the rhymes to get to and from Dragon Land are spoken twice.
Near the end of Zak & Wheezie's performance in the Two-Headed Dragon contest in "Calling Dr. Zak," there appeared to be a large number of audience members watching them, but after the camera paned over to the band and back, only Dr. Booboo Gone, Quetzal, and three stock dragons were in the audience.
In "Calling Dr. Zak", after Zak hears somebody scream from the doctor's cave, he turns his head around (to the right) to talk to his friends, but the spikes on his neck move as if he turned his head to the left.
After Zak exclaims that going to the doctor will hurt him, the camera pans over to Max, Emmy, and Cassie, and the first time Max blinks, his eyes move about an inch up to his eyebrows, and then move back down to where they were.
After Max talks about being afraid of the doctor when he was "little" in "Calling Dr. Zak", a white glitch appears by Zak's eye for a couple frames.