Does anyone know this format?

[Lexou Duck]

I've looked into quite a few games in my time, and i can tell you unknown file formats are almost always just developer-exclusive formats.

Now are you sure those are the sprites ?
If they are, it's probably some kind of compression format, or maybe palette data, or even music, i dunno

i tell ya, if you can't find a third party software to convert these files into something usable by regular geeks, chances are it's not the filetype you're looking for, or nobody was interested in a boy and his blob. :/