Monstrous Monday: The Olitiau

The Olitiau are giant bats. Large enough and strong enough to serve as a steed for those that know how to summon them. Most often witches, fey, and goblinoids.
Orcs will sometimes use the larger and more monstrous varieties as steeds in battle. These are often called "Orc War bats".

Olitiau (Monstrous Riding Bat) 
Basic-era stats
No. Enc.: 1d12 (4d6)
Alignment: Neutral (Chaos)
Movement: 180' (60')
            Fly: 360' (120')
Armor Class: 5
Hit Dice: 5
Attacks: 1 (bite) or Sonic shriek
Damage: 1d8 or see below
Save: F4
Morale: 10
Hoard Class: None
XP: 135

Olitiau are giant bats. Found in deep, dark caves these creatures can be used as steeds for those that know the secrets of summoning them or for subterranean races that speak their language.
Like Giant Bats (qv) these creatures can also be vampiric, though the percentage is much higher, 45%.  The bite of an Olitiau will not cause a living creature to rise as a vampire though.
The Olitiau have a bite attack and sonic shriek.  They can use one or the other once per round.  The sonic shriek is a cone 5' at it's base (mouth) and extends 120' long and 40' wide.  Creatures caught in this area take 1d6 points of damage and must save vs. Paralyzation or be stunned (unable to attack) for 1 round.  The Olitiau can extend this range to 360' long and 120' wide, but only creatures of less than 1 HD are affected then.
Olitiau do not fare well in sunlight and are at a -2 on all attacks.  They are unaffected by darkness of any sort including magical darkness.

Summon Olitiau
Level: Druid 2, Wizard 2, Witch /Warlock 2
Duration: 24 hours
Range: 60 miles
By means of this spell, the caster can summon one* Olitiau to serve it for 24 hours.  The olitiau must be treated well and given its body weight in fresh meat to eat.  The olitiau will operate as the steed for the caster and even attack whomever the caster directs it to attack.   Most often the olitiau are summoned as steeds and can carry 300lbs of weight.
The olitiau can only be summoned at night or underground where it is dark.
At higher levels the caster can summon more Olitiau.
At 7th level the caster may summon two, at 9th 3 may be summoned and so on for every other level to a maximum of 8 olitiau at level 19.