WATCH: David Muir shares Texas high school principal’s surprise from graduating class

A beloved high school principal who’s affectionately known as “Coach Mutt” was surprised with a heartfelt, handwritten letter to him at graduation.

​A beloved high school principal who’s affectionately known as “Coach Mutt” was surprised with a heartfelt, handwritten letter to him at graduation.  WNT A beloved high school principal who’s affectionately known as “Coach Mutt” was surprised with a heartfelt, handwritten letter to him at graduation.