Continuity mistake: After the chief stops his mother telling scary stories, pictures drop behind the kids. The one to the left of the one of Maui has three creatures with spiky heads. After the chief is knocked over we see those pictures again, and the one of three creatures has been replaced by one of an island with a cloud above it.
Continuity mistake: After Moana narrowly escapes drowning, she drags herself ashore next to some debris from a boat, one large piece especially, being by her right hand. After the pig runs away, she's not moved, but the debris around her has changed, and the large piece has disappeared.
Continuity mistake: When Moana goes back to Te Fiti after Maui left, she puts Hei Hei in a basket inside the boat, but when she gets almost hit by a boulder the heart bounces away and Hei Hei appears, and gives it back to her, then never shows up again until the end of the movie. Where did he come from?