So, waiting for the session to start. Here's what I did.
Took the standard Bugbear Strangler, turned him into a level 4 elite, and made its Strangle at-will into a Reliable Encounter power that knocks prone and slides. Said bugbear also has a minor-action attack (1d8+4). I think he lacks anything to do, but again, I don't anticipate he'll survive too long (or he'll bolt).
The second bugbear is a Bugbear Shadow Walker, made a 4th level elite. He gets the same minor action attack as the Strangler, and his Blur of Movement recharges on a 4-6 and when first bloodied. I am tempted to give him Combat Advantage +1d6, just to be a bastard.
The field has a few snares (attack that restrain and dangle someone 20ft up), and a few maidens kiss minion traps.
Then there are the three Snow Sharks:
4th level Skirmisher; 50 HP; AC: 18, Fort/Ref: 16, Will: 15. Speed 8, Tremoresense. Bite: 1d6+4 (and +1d6 if the target is prone). If they charge, a target is knocked prone. Melee mobility (so move and attack), and a free IR charge if an enemy is bloodied within 5. If they have moved at the end of their turn, they have concealment.
I shall report how it goes.