Some experimental textures included hair on creatures, but in the end, that feature was left behind.

some creatures with fur were shown earlier in the book, though given that theyre unpainted it looks more like a scrapped part

and that also more closely matches the fur in some 2006 creature renders. these could have actually just been a scrapped hair part

which lines up with these models still found in retail

but these look more like a part of the skinpaint system, were there two different hair systems in place? (second image is from the prima guide)

and yeah there was more evidence there was hair paint systems, like these properties (Spore_Game.package\editor_hairSystem~\hair.prop). hair also has its own shaders which just a part wouldnt need

specifically it features dwibble, and doweeblie. this actually connects these creatures together!

the above two pngs are from retail, but they look pretty similar in feb 19 too. both were white/grey, and are now green in retail

its not present in that render, but its also very possible dweebeeble, who went through the same color changes and has a lot of the same parts, is related to these two as well