Well, now it is! A wiggler frozen in an ice block. Contains both 7-colour (half a palette row) and 15-colour (full palette row) versions. They both use the same map16. Acts like a cement block, and to make it slippery either toggle that setting for the level or use a custom slippery block.
It uses BG2 slot. It combines a Wiggler graphics with Super Mario Maker's Frozen Blocks.
I fail to see the use of this, but I appreciate the effort all the same.
The original graphic was actually a request from someone lost to time, and on the Remoderation Removal Archive, someone asked if it was in there. It seems there's demand for this thing, so I used it as practice in reducing to 15/7 colours a partially-transparent object that contains another object.