From Muppet Wiki

The Muppets

Animal

• Baby Animal (Muppet Babies)
• Baby Animal (A Muppet Family Christmas)
• Kid Animal (Muppet Kids)

Beaker

• Baby Beaker (Muppet Babies)
• Kid Beaker (Muppet Kids)

Bean Bunny

• Baby Bean Bunny (Muppet Babies)
• Kid Bean (Muppet Kids)
• Grandpa Bean Bunny (The Tale of the Bunny Picnic)

Bunsen Honeydew

• Baby Bunsen (Muppet Babies)
• Kid Bunsen (Muppet Kids)

Fozzie Bear

See: Fozzie Bear Alternate Ages

Gonzo

See: Gonzo Alternate Ages

Janice

• Baby Janice (Muppet Babies)
• Kid Janice (Muppet Kids)

Kermit the Frog

See: Kermit the Frog Alternate Ages

Miss Piggy

See: Miss Piggy Alternate Ages

Robin the Frog

• Baby Robin (Muppet Babies)

Rowlf the Dog

• Baby Rowlf (The Muppets Take Manhattan and A Muppet Family Christmas)
• Baby Rowlf (Muppet Babies)
• Kid Rowlf (Muppet Kids)

Sam the Eagle

• Old Sam (The Muppet Christmas Carol)

Scooter

See: Scooter Alternate Ages

Skeeter

• Baby Skeeter (Muppet Babies)
• Kid Skeeter (Muppet Kids)

Statler and Waldorf

• Young Statler and Waldorf (The Muppet Christmas Carol, Kermit's Swamp Years, and Statler and Waldorf: From the Balcony)
• Uncle Statler and Uncle Waldorf (Muppet Babies)

Sesame Street

Bert

• Baby Bert (Sesame Street Babies books)

Big Bird

• Baby Big Bird (Sesame Street Babies books and Sesame Beginnings videos & books)

Clementine

• Baby Clementine (Sesame Street Episode 2313)

Cookie Monster

• Baby Cookie Monster (Sesame Street Babies books and Sesame Beginnings videos & books)

Count von Count

• Young Count (Sesame Street: "The First Day of School")

Elmo

• Baby Elmo (Elmo's World and Sesame Beginnings videos & books)

Ernie

• Baby Ernie (Sesame Street Babies books and Sesame Beginnings books'')

Forgetful Jones

• Baby Forgetful Jones (Sesame Street Episode 2313)

Grover

• Baby Grover (Sesame Beginnings books)

Oscar the Grouch

• Baby Oscar (Sesame Street Episode 2313)

Prairie Dawn

• Baby Prairie Dawn (Sesame Street Babies books and Sesame Beginnings videos & books)

Zoe

• Baby Zoe (Sesame Beginnings books)

Fraggle Rock

Cotterpin Doozer

• Baby Cotterpin (Fraggle Rock 119)

Gobo Fraggle

• Young Gobo (Fraggle Rock 120, 121, )

Junior Gorg

• Baby Junior (Fraggle Rock 120)

Storyteller Fraggle

• Young Storyteller (Fraggle Rock 315 and 502)

Traveling Matt

• Young Matt (Fraggle Rock 315 and 502)