I think the hashtag name of the cow spot texture is #5AEF7671, at least from the icon. I also looked around the unpacked data for a bit and I believe the texture data is actually in the Spore_Game package (in the #406A0200 folder), not the Spore_Graphics folder 'cause that's where most of UI files are stored.
There is also something that I need to point out, the game files tend to be confusing and misleading at times, and this is a big problem with people modding Spore (and possibly other EA titles). Certain data that you are seeking may be stored in a different package file entirely, or have a different folder name altogether. For instance, the part icon you commonly see in the editors mostly have a hashtag name, and that's where one can find the file, but in reality most of the data linking to that part has a "cleaner" folder name.
Let me explain, the Sassysquatch foot icon has a hashtag name of #9F0C67F7, so one can find the file in there, but the other parts of it is actually ce_movement_primate_04.rw4 (both in the LOD and non-LOD folders). This is because the icons mostly refer to the left side of the part, and the right side (even the middle, if possible) is stored in a different file name and in a lot of different locations. Granted, it's all in the Spore_Graphics package file where the UI icons are, but it's something a lot of people can miss (even me when I was trying to fix a problem with DI and it didn't turn out successfully for some reason). Textures are not like this, as the data is still referring to the hashtag name, but it's still something a lot of people need to watch out for.
Ripper of Spore: Unofficial Galactic Score and... that's about it.
"Raggedy Ann scares me!"