Yoyo and Doc Croc actually ARE the Brothers Grimm, Jacob and Wilhelm reincarnated into plushie bodies and brought to life by magic
- The reason they enter the fairy tales is that their own characters got so strong they have to police them for happy endings. Basically, Yoyo and Doc Croc are fairy tale cops as well as the Brothers Grimm.
Yoyo is a kobold
- The wolf kind of kobold, not the lizard one.
Doc Croc is a wizard, albeit not powerful one
- He seems to know magic very well and is able to use magic in Rapunzel episode.
- Yoyo and Doc Croc go into stories and get involved with them, meet the characters and inspire them to go onto their happily ever after. The Eto Rangers' jobs are to go into stories and iron out any changes caused by outside forces. So, whenever Yoyo and Doc Croc are finished traveling through the world of a Brothers Grimm tale, the Rangers have to go clean up after them.