By far, my favorites of these bizarre Disney/Thornberry mash-up GIFs are the ones from Beauty and the Beast and Tarzan...
Belle steps out of the house with Nigel's face

The rooster didn't have a legitimate reason to be started before. Now it does!
Belle is so happy with the library's book selection that she becomes a Thornberry

Nigel's face close-up is purely frightening at the end of this GIF.
The Beast in human form... has Nigel Thornberry's face!

Can you imagine if Belle had been through all of that with the Beast, and his human face ends up looking like that? Hilarious and tragic.
Tarzan shares a moment with Jane

Even with Tarzan's body, I find it unlikely Jane would find Nigel's face attractive enough to fall in love with.
Tarzan jumps through the branches

Baby Tarzan as Nigel

The Thornberry's are the ones who abandoned Tarzan as a baby! I knew it.
Bonus! Jasmine, The Little Mermaid, and Pocahontas all morph into Nigel Thornberry

A whole new world, and a whole new face!

Outta the sea, wish I could be... a Thornberry.

Don't shoot! It's me, Pocahontas! I swear.