Here's one of the customized monsters I used for my session last night. Against a bunch of 12th level Gestalt characters they can't do much individually, but put 30 of them on the board and they were awfully fun to push around.
Medium Outsider (Evil, Extraplanar, Lawful)
Hit Dice: 6d8+12 (39 hp)
Speed: 20 ft. (4 squares)
Armor Class: 15 (+4 natural, +1 Dex) touch 11, flat-footed 14
Base Attack/Grapple: +6/+8
Attack: Claw +8 melee (1d4+2)
Full Attack: 2 claws +8 melee (1d4+2)
Space/Reach: 5 ft./5 ft.
Special Attacks: -
Special Qualities: Damage reduction 5/good or silver, darkvision 60 ft., immunity to fire and poison, mindless, resistance to acid 10 and cold 10, mindless, see in darkness
Saves: Fort +9, Ref +8, Will +8
Abilities: Str 15, Dex 12, Con 14, Int -, Wis 13, Cha 3
Environment: A lawful evil-aligned plane
Organization: Solitary, pair, gang (3-5), swarm (6-15), or mob (10-40)
Challenge Rating: 5
Alignment: Always lawful evil
Level Adjustment: -
A smoldering lemure looks much like a larger version of its more common cousin, standing about 6 feet tall and weighing about 200 pounds. They stink of sulphur and putrid bubbles in their flesh are constantly popping and emitting vile smoke.
Smoldering lemures are mindless and cannot communicate, but they are sensitive to telepathic messages from other devils, typically obeying a devil's mental commands.
Smoldering lemures surge toward anything they meet and try to claw it apart. Only a telepathic command from other devils or the complete destruction of the creatures can make them stop.
A smoldering lemure's natural weapons, as well as any weapons it wields, are treated as evil-aligned and lawful-aligned for the purpose of overcoming damage reduction.
Mindless (Ex): Immunity to mind-affecting effects (charms, compulsions, phantasms, patterns, and morale effects).
Burn (Ex): When a smoldering lemure hits with a claw attack, the opponent must succeed on a DC 20 Reflex save or catch fire. The save DC is Constitution-based. The flame burns for 2d6 points of damage for 1d4 rounds if not extinguished sooner. A burning creature can use a full-round action to put out the flame.
Inspiring Game Images - Gamma World
11 minutes ago