If you've ever seen a movie where they show a much younger or older version of one of the main characters and thought, “that actor really looks like he could be the other person at another age,” then you'll enjoy the blog Kidcasting.
1Kids In The Hall
Mark McKinney as Chicken Lady.
2The Mighty Boosh
Julian Barratt as Howard Moon and Noel Fielding as Vince Noir.
3It's Always Sunny In Philadelphia
Charlie Day as Charlie Kelly, Rob McElhenney as Mac, Glenn Howerton as Dennis Reynolds and Kaitlin Olson as Sweet Dee Reynolds.
4The Sarah Silverman Program
Sarah Silverman as herself, Laura Silverman as herself and Andy Samberg as Andy, Sarah's imaginary friend.
5Tenacious D in The Pick of Destiny
Jack Black as JB and Kyle Gass as KG. (Creative names, guys.)
6Austin Powers In Gold Member
Mike Myers as Austin Powers, Mike Myers as Dr. Evil and Robert Wagner as Number Two.
7Hot Tub Time Machine
Rob Corddry as Lou Dorchen, John Cusack as Adam, Craig Robinson as Nick Webber and Clark Duke (who doesn't change) as Jacob.
8Jay and Silent Bob Strike Back
Jason Mewes as Jay Kevin Smith as Silent Bob.
Tina Fey as Liz Lemon and Alec Baldwin as Jack Donaghy.
10Bill & Ted's Bogus Journey
Alex Winter as Bill S. Preston, Esquire, and Keanu Reeves as Ted Logan.
David Spade as Joe Dirt.
12The Sarah Silverman Program
Brian Posehen as Brian Damien Spukowski.
Bill Murray as Frank Cross.
14It's A Wonderful Life
Jimmy Stewart as George Bailey and Donna Reed as Mary Hatch.
Tom Hanks as Forrest Gump and Robbin Wright as Jenny Curran.