Life as a Musician
Dean was the lead singer of a famous band called Greensuit. While singing for the band, he used a stagename, "Cole Dennis". The group released several records before splitting up.
Chronology: TV Series
Mr. Collins was first introduced in the episode "A Service to the Community." The guardians think he is the beast from Meridian, and attack him. It turns out that he isn't the beast. Will says," I can't believe we zapped our history teacher!" They return him home and hopes that he thinks it was all a dream.
In season 2, Will finds out that Mr. Collins and her mother are dating in "H is for Hunted." She is very upset about this. She stays upset about this until "M is for Mercy," when she sees Mr. Collins saving her mother's life while in her guardian form. She forgives him and invites him over for dinner.
- Mr. Collins' name is actually a pun. A "Dean" is a person with authority in a specific academic field, or an area of concern, or both. So, Professor Collins would be the Dean of History.