Parody of copyrighted works can be fair use in the US, but whether this would count is borderline. Simply using Frog and Toad to tell an unrelated story wouldn't be parody, but there are jokes that tie back to the F&T books which help make the case that this is a real parody.
It also helps that this is not commercial and doesn't have negative impact on the originals.
infinitebit · · focus · HN ↗
jefftk · · focus · HN ↗
It also helps that this is not commercial and doesn't have negative impact on the originals.
ceejayoz · · focus · HN ↗
This is 100% fair use by the standard.
axus · · focus · HN ↗