You would need adapters for any conventional band to work on the Apple Watch. I'm afraid I can't make any recommendations regarding adapters because I don't own any. I own only Apple Sport bands at present.
Do you really have cartoon character watch bands that wide? I actually do have Hello Kitty and possibly a Frozen watch band around here somewhere. I am a mother, aunt, great-aunt and babysitter to many kids, so of course there are cartoon character watches somewhere in my possession. I can't say that I've seen any wide enough to look decent on an Apple Watch. The ones that might be are going to look really cheap and odd on an Apple Watch.
And Dora...she's a lovely lass and my kids loved her once upon a time but they run screaming from the room now if I sing her theme song.
If I really want to terrorize them I get out the Dora doll and wave her around saying "Say backpack!" I save that for times when they pluck my last nerve and I feel like being Evil Embarrassing Mom.
So...are you sure about that Dora band?