Which are very, VERY seldom seen (and also currently useless, due to no recipes using any as ingredients). Because they are dropped from Slooms, Sleep-inducing slimes.
What happened to those? They are not available anywhere else than Monster Cages (with low chances of appearing), now that the levels they are from were pulled from the game.
Said levels? Starlight Cradle, a set of stages apparently filled with Slooms. And some stuff.
What was the motive behind this, though? Was the status it focused on too broken for players? Did the gears with stronger weakness to Sleep not sell? Are they planning a release of it with a boss (thus new tokens)? Or is it because the weapons you'd get with said tokens would be too broken BECAUSE they'd induce sleep?
It's kinda new to me, so I feel a discussion on this would be worthwhile.
The "and some stuff" were energy turrets. These are back in the game again in select levels since the most recent update.
As for why Starlight Cradle is MIA, that's something only the Devs know for sure. Those levels certainly were fun. The mini boss floor "Torpal Titian" was where you went to get disassembled by piercing attacks and sleep status. My sleep resist Silvermail was so useful then.