"U" is for "Uligin"

Uligin  ("Murkbird")

No. Enc.:  1d4 (1d4)
Alignment:  Chaotic
Movement:  30' (10')
         —Fly:  90' (30')
Armor Class:  5
Hit Dice:  12
Attacks:  3 (2 claws, 1 bite)
Damage:  1d4 / 1d4 / 1d8 + poison
Save:  L12
Morale:  8
Hoard Class:  XV
XP:  4,400

The Uligin (both singular and plural), also called "murkbirds" or "blackheart birds", are hefty, 10' tall feathered fiends of demented intelligence and cruelty. Their nausea-inducing reddish / greenish / blackish coloration reflects the foulness of their twisted souls.

A uligin can generate a roiling cloud of oily darkness up to 60' in diameter around itself. Those caught inside suffer three effects:  they are Blinded [see p. 36 of the Mutant Future Core Rules], take damage as if within a Vampiric Field [p. 31, with the damage going into a reserve pool, as well], and lose -2 to Morale.  The Uligin are completely immune to any and all effects of these clouds.  Their saliva also teems with germs, and acts as an effective Class 3 poison.

While most uligin are content to bully and terrorize rural communities, exceptionally ambitious specimens become bandit kings and crime lords.  These nasty individuals lead gangs of 3d6 mutant hooligans of all stripes.

Mutations:  Enhanced Vision (Night Vision), Mind Reflection, Toxic Weapon (Venom), Unique Mutation ("Miasma Generation")