A Gummi By Any Other Name - S1-E9
Continuity mistake: During most of this episode, Princess Calla wears ragged peasant's clothing. But in the instant where she uses the Changing Hat to transform into Igthorn, she wears her usual princess dress.
A Gummi By Any Other Name - S1-E9
Plot hole: The Changing Hat has the habit of transforming its wearer at the mere mention of a name (or even a species type, as seen before when Sunni accidentally transforms into an ogre). However, when Calla impersonates Igthorn and faces off against him, she loudly says the name "Toadwart" and doesn't transform.
A Gummi By Any Other Name - S1-E9
Continuity mistake: First Cavin runs out of the prison tower, then the Gummis (Sunni, Tummi and Grammi), and then Igthorn, each of them smashing the door into the guard's face. But in the instant where the Gummis appear, Princess Calla is missing even though she is supposed to be with them.
A Gummi By Any Other Name - S1-E9
Continuity mistake: When Cavin climbs the wall of the prison tower, he accidentally dislodges a stone which falls onto the helmet of the ogre guard beneath. But in order to do so, it would have had to fall round a third of the tower's width, since Cavin is climbing out of the guard's sight.
The Secret Of The Juice - S1-E10
Continuity mistake: When Tummi goes looking for Zummi, Gruffi and Cubbi, he arrives right outside the barrel room. When first seen, the barrel room door is smooth, but in the next close-up the door suddenly has an iron grill window in its surface.
The Oracle/Someday My Prints Will Come - S1-E12
Continuity mistake: When the mechanical footprint machine topples, it lands with its heel up and its toes down. When we next see it, the toes are pointing up.
The Oracle/Someday My Prints Will Come - S1-E12
Continuity mistake: The Oracle: When the oracle confronts Tummi for his con game in the final scene, the square before it is empty. But just when Tummi promises never to eat again, two Gummiberry baskets suddenly appear to the left of the stone head's mouth.