There is a big park a few blocks from me where my dog Milo and I spend a lot of time. There are lots of sculptures scattered around this town and one in the park is particularly odd. Someone told me it's called "The Troll". Milo growled and barked the first few times he saw it.
Too bad there's nothing to show scale because it's a fair size. When I walk by, the ass crack is almost face high.
A long time ago, I heard that there was no medical term or name for ass cracks and Gluteal Cleft was suggested.