Emmet

"Mrs. Graves, Mike has stepped over the yellow line."

          -Emmet after seeing Mike break the rules.

Emmet is a minor character in Monsters University.  He is a student in Karen Graves's class. He is the first to notice that Mike Wazowski steps over the yellow security line just to see Frank McCay scaring. It is unknown what Emmet became after he grew up.

Monsters University
After Mike steps over the yellow line, Emmet tells the teacher, and the whole class panics.

Trivia

 * Emmet's only line could make a reference to Kathy, the fish in Finding Nemo that first notices that Nemo swims out the sea to touch the boat.