I have tagged this with "pompom" (singular) as there is only one, but that makes it the only cheerleader image of its kind. Meanwhile there are many other images with the "pompoms" (plural) tag.

What to do? Nothing? It brings to mind the situation of the tags "knives" and "swords" which default to plural, even if one only inputs them in singular (due to there only being one visible).

fuck you, it's pompoms

For Danbooru, go with whichever one is on the tag. Plurals or not doesn't really matter, but the default here is to make it plural.