I was thinking. We've pretty much got sleep sort of implemented into the game already, right? There's sleep-resistant shields and armor with weaknesses to sleep. Heck, there's even a jelly that causes sleep, even though it's rarely seen.

So why don't we have a sleep stratum theme?
Here are possible names for sleep enemies:
Narcolisks work like other status chromalisks, spitting out a sleep-inducing goop.
Somnibots are normal shufflebots with sleeping bullets.
Slackilites throw stuff like pillows, blankets, and cushions at knights, as opposed to the usual office supplies.
Diamond Greavers work like regular greavers, with higher-tier ones creating hazes of knockout gas on successful swoops.
Katnaps attack like regular kats, but even when they're in their "scary" mode, the eyes will stay sleepy and only half-opened.
Coma Knights, in later tiers, have charge attacks that cause a mist harvested from Sloombargos to appear around them.
Dirt Nappers have all the attacks of a regular zombie, but with the added chance of causing sleep.

Also, possible level names:
Candlestick Keep: Dirt Nap Nightmare
Lichenous Lair: The Combination of Dreams
Wolver Den: Comatose Crunching
Devilish Drudgery: Sleeping on the Job
Sleep Bash Arena: Slimey Showdown, Beastly Brawl, etc.
The Starlight Cradle levels could come back too. That's be fun, especially since I only knew they existed because of the wiki.

If any of you guys have good ideas for names, I'd love to hear them. As you can see, I'm not that creative with names, so any help would be greatly appreciated. Replace the names I suggested if you think they suck!

Also, since I only thought of level and monster names, check out this guy's post: http://forums.spiralknights.com/en/node/41835
He knows how to balance things! Plus, he's got a sleep-themed gun puppy practically already designed.