Suggestions by @user_111056

Daffy Duck

as Humpty Alexander Dumpty in Harold

Bridgette (Total Dramarama)

as Dronkeys in Harold

Courtney (Total Dramarama)

as Dronkeys in Harold

Lola Bunny

as Kitty Softpaws in Harold

Bugs Bunny

as Puss In Boots in Harold

Bo Peep

as Mama Luna in Harold

Insectosaurus

as Giant in Harold

SpongeBob SquarePants

as Ethical Bug in Harold

King Andrias

as Big Jack Horner in Harold

Shadow the Hedgehog (Sonic X)

as Death in Harold

Kion

as Baby Bear in Harold

Simba

as Papa Bear in Harold

Nala

as Mama Bear in Harold

Isabela Madrigal

as Goldi in Harold

Toad (Nintendo)

as Perrito in Harold

Yoshi (NIntendo)

as Perrito in Harold

Scratte

as Great Terror in Harold

Baby Scrat

as Golden Goose in Harold

Mum (Horrid Henry)

as Imelda in Harold

Courtney (Total Drama)

as Jill in Harold