The Thrice Cream Man/The Flibber-Flabber Diet - S1-E7
Other mistake: In "The Flibber-Flabber Diet," Chowder and Truffles return when Mung calls them. How could they hear him when they'd already left?
Other mistake: As Mung is held by Schnitzel, only Schnitzel's shadow is behind him, when it should be both.
Burple Nurples/Shnitzel Makes a Deposit - S1-E2
Continuity mistake: In "Shnitzel Makes a Deposit", Truffles tears off a check from a checkbook and gives it to Shnitzel. A few shots later, the page where she tore off the check is back to normal.
Grubble Gum/The Cinnamini Monster - S1-E3
Mung: We need more spice!
Truffles: Well, I'm glad one of us finally acknowledged it.