Creeper preemptively strangling himself as he goes to deliver bad news to the Horned King.
In the beginning, when Taran is boasting to himself about his perceived or wished abilities. By doing so, he loses sight of the pig. Yep, that's right, he couldn't perform the simple job of keeping the pig near him because of his dwelling on his own competence.
When Gurgi offers his partially eaten apple as part of the bargain deal. It's hilarious and a little sad because it holds such value to him.
Interestingly enough, the Horned King actually provides a funny quote: