I’ve seen people attempt to upload photos of bigfoot, but they are always the same images taken from the internet that show up on reverse image search (so copyright infringement and not evidence of an organism).
And I’m surprised lotteryd didn’t mention it, but lots of weird oddities hang out in the unknowns because no one knows what to do with them.
Modified link here: https://www.inaturalist.org/observations/identify?per_page=100&iconic_taxa=unknown&order=asc&without_taxon_id=67333%2C131236%2C151817
and relevant forum post here: https://forum.inaturalist.org/t/amount-of-unknown-records-is-decreasing/8594