Entertainment Tonight ET Online ETOnline.com

When it comes to casting parents, Glee's cup runneth over.

Carol Burnett played Sue's mother, Jeff Goldblum played Rachel's dad and don't even get us started on the brilliance that is Mike O'Malley as Burt Hummel.

RELATED - Glee Star Reveals "I Won't Be Back Next Season"

On this Tuesday's all-new episode, Glee's family tree adds one more member as Puck's papa comes to Lima for the first time, and is played by Melrose Place alum Thomas Calabro!

RELATED - Glee's Graduation Playlist Revealed

Unfortunately for Puck, his father shares more than a passing resemblance with the dastardly Dr. Michael Mancini that Calabro memorably played for seven years (not counting his participation in The CW's reboot). Check out an ETOnline exclusive sneak peek above and you'll quickly find out why Puck's bad dad should have stayed away!

Glee airs Tuesdays at 8 p.m. on Fox.