I'm pretty sure the Animorphs toyline would meet the definition of Obscure as laid out in this thread.
They did have a book series and show, but neither were Transformer branded (only the toys were).

I do have a question though and sorry if it's already been answered, but if the same character has different toys within the same line is it no longer obscure?
For instance most of the Animorph characters got different toys. So is Ax not obscure because he has a toy that turns into a scorpion and another that turns into an andalite?

If the answer to the above question is yes, then the only truly obscure Animorphs are Rachel and Taxxon.