First thing's first, I downloaded an excellent fan-made adventure for D&D Next called Rats in the Sewer (I'd ask that any of my players who reads this NOT look at the adventure, which I plan on running at some point). While I may run it for D&D Next, I was also thinking that it would work pretty well with 13th Age, since the simple-to-create-monsters in that system makes adventure conversions very easy. The adventure uses monsters from the Bestiary of the first D&D Next playtest packet, not all of which are currently available in the Escalation Edition of 13th Age. So I figured I'd write up some stat blocks for them.
Fire Beetle Level 1 Troop Initiative +2
M Bite +6 vs AC, 4 damage
AC 18 PD 15 MD 11 HP 26
Luminescent Glands: Fire Beetles emit their own source of dim light.
Giant Centipede Level 1 Mook Initiative +3
M Bite +5 vs AC, ongoing 3 poison damage
AC 16 PD 15 MD 11 HP 7 (to kill a single mook)
Grey Ooze Level 2 Wrecker Initiative +4
M Slam +7 vs AC, 8 acid damage; +4 damage and daze on a natural 16+
AC 15 PD 13 MD 10 HP 50
Resist 16+ cold and fire damage, Blindsight, can climb vertical surfaces at full speed
Gelatinous Cube Large Level 3 Troop Initiative +3
M Slam +8 vs AC, 20 acid damage and engulf (save ends) on a natural even hit
AC 18 PD 17 MD 13 HP 100
Engulf: Target takes 10 acid damage at the start of its turn; up to 3 creatures
Blindsight, Transparent (increase DC to spot it by +5)
Goblin King Level 2 Leader Initiative +6
M Short Sword +7 vs AC, 6 damage (9 if target is engaged with ally)
R Short Bow +7 vs AC, 6 damage, nearby allies can roll attacks twice against target and use better result
AC 18 PD 16 MD 13 HP 40
Disengage +5 (only needs to roll a 6+ to disengage)
Human Barbarian Warrior Level 2 Wrecker Init +5
M Longspear: +7 vs AC, 7 damage + Reach Tricks
OR M Greataxe: +6 vs AC, 10 damage
R Javelin +7 vs AC, 6 damage
AC 16 PD 17 MD 12 HP 40
Reach Tricks: If equipped with Longspear, 1/battle succeed at a normal save to use reach to your advantage (attack enemy you're not engaged with, OA vs enemy who disengaged + moved, OA vs enemy who engages, etc).
Comments and criticisms welcome. 13th Age is currently available for preorder.
EDIT: Changed stat blocks so that damage expressions are in line with EE3; removed goblin warrior since Goblin Grunt is now a troop instead of a mook.