Ian Casselman (Mr.Fantastic) the drummer for Canadian pop-punk band Marianas Trench, possibly the awesomest person ever.
Me: "I just got a message from Ian Casselman from Marianas Trench on myspace, and I GOT A SIGNED POSTER and it says "IAN=D"."
by xMelissaMarie October 20, 2007
1 more definition
Ian Casselman is the drummer of band Marianas Trench. He is most commonly found on tour with band and in your children's closets.
I saw Marianas Trench last night in Vancouver, Ian Casselman had creepy side burns!
by Marianas Trench Wench September 01, 2010