DFTWTM

Cast
Count Duckula (from Count Duckula) as Big Bird

Brian (from Family Guy) as Snuffy

Amy (from Sonic) as Zoe

Garfield (from Garfield) as Bert

Pingu (from Pingu) as Ernie

The Pink Panther (from The Pink Panther) as Grover

Winnie the Pooh (from Winnie the Pooh) as Sherlock Hemlock

Mr. Happy (from The Mr. Men Show) as Baby Bear

Duck (from Thomas the Tank Engine) as Kermit the Frog

Rolf (from Ed, Edd n Eddy) as Guy Smiley

Kimi Finister (from Rugrats) as Grudgetta

Stewie (from Family Guy) as Oscar The Grouch

Pingi (from Pingu) as Abby Cadabby

Theodore Tugboat (from Theodore Tugboat) as Elmo

Diesel 10 (from Thomas) as Frazzle

Sally (from Cars) as Betty Lou

Version 1 (made by DonaldDouglas910)
BJ (from Barney And Friends) as Big Bird (BJ and Big Bird are both yellow and bossy, BB isn't bossy on purpose)

Digit (from Cyberchase) as Elmo (Not Snuffy!)

Bagheera (from The Jungle Book) as Ernie

Tiger (from Skunk Fu) as Bert

Mr. Grumpy (from The Mr. Men Show) as Oscar (Not Michael from Barney and Friends because Michael is happy)

Scar (from The Lion King) as Cookie Monster

Riff (from Barney and Friends) as Grover

Zurg (from Toy Story 3) as Frazzle

Barney (from Barney and Friends) as Mumford

Delete (from Cyberchase) as The Shrimp

Matt (from Cyberchase) as Humphrey

Mr. Rude (from The Mr. Men Show) as Wolfgang

Buzz (from Cyberchase) as Honker

Inez (from Cyberchase) as Ingrid

Baby Bop (from Barney) as The Countess

Mr. Messy (from The Mr. Men Show) as The Count von Count

Doc (from Snow White) as Papa Bear

Mr. Bump (from The Mr. Men Show) as Baby Bear

Eric Cartman (from South Park) as Telly Monster

Jackie (from Cyberchase) as Prairie Dawn

Dopey (from Snow White) as Natasha (Both silent)

Version 2 (by 47 contributers)
Mario (Mario) =Big Bird

Pingu (Pingu) =Elmo

Mr. Happy (Mr Men Show) =Ernie

Mr. Stubborn (MMLM) =Bert

Hoops (Hoops and Yoyo) =Grover

Yoyo (Hoops and Yoyo) =Cookie Monster