Teacher is a fanmade Back to School Sing-a-ma-jig. She is pink, has purple hair, has the same ears as the big one from the Red Sing-a-ma-jig Duet, has purple heart eyes, a yellow nose, a light bluish-green mouth, the same arm pose as the Reindeer Sing-a-ma-jig, has the same feet as the big one from the Orange Sing-a-ma-jig Duet, has a purple shirt with a red tie and letters on it, has the same voice as the Violet Sing-a-ma-jig and she sings "The Alphabet Song". She signs on by saying "Good morning!", enters song mode by saying "A-B-C song!" and signs off by saying "Bye Bye!".
Teacher sing a ma jig

This is what she looks like.