This 1918-S wheat cent has a rim cud on the reverse at about 2:30. That part's already documented. It lines up with Cuds on Coins CU-1C-1918S-01R, and it's very likely the same reverse die.
What's interesting is lower down. Between about 3 and 4 o'clock there's a pre-cud, a heavy die crack where a piece of the die had started to break loose but hadn't come out yet. It's a separate failure from the rim cud, not the same break.
The Cuds on Coins example for 01R is pretty worn, so you can't really tell whether it had the pre-cud. You can just make out the faint top of a die crack in the same area, but there's no way to know if that's the start of the pre-cud or if wear took the rest of it. So either the 01R die had this pre-cud all along and it just doesn't show on their coin, or this is a later die state.
Either way it wasn't recorded, so I catalogued this die state and cross-referenced it to 01R. If anyone has a 01R in a different die state, I'd love to see whether the crack is there.