Bat Mitzvah Crashers/Super Secret Weakness - S1-E5
Continuity mistake: In "Li'l Orphan Happy" when Ben makes his mom the tuna salad, it has lettuce around it, but in the close-up the lettuce disappears. When it gets zoomed-out on, the lettuce is back.
Artificial Unintelligence/We Got the Bee - S1-E3
Continuity mistake: When the baby comes rolling down the hill to Gwen's house on the taffy cart, Happy picks up the baby and leaves the taffy cart outside. But when Bessie and Penny try to run inside right after that the cart disappears.