FREQUENCY: Uncommon

FREQUENCY: Rare ([Cold Wilderness Swamp])
FREQUENCY: Uncommon ([Cold Freshwater Surface], [Temperate Freshwater Depths]) <check this line>

FREQUENCY: Rare ([Temperate Wilderness Swamp])
FREQUENCY: Uncommon ([Temperate Freshwater Surface], [Temperate Freshwater Depths])

FREQUENCY: Rare ([Tropical Wilderness Swamp])
FREQUENCY: Uncommon ([Tropical Freshwater Surface], [Tropical Freshwater Depths])

NO. APPEARING: 2-24
ARMOR CLASS: 4
MOVE: 6 // 12"
HIT DICE: 4+4
% IN LAIR: 20%
TREASURE TYPE: [A]
NO. OF ATTACKS: 3 or 1 ~ 15
DAMAGE/ATTACK: 1-6/1-6/2-8 or by weapon
SPECIAL ATTACKS: [SB]
SPECIAL DEFENSES: Camouflage
INTELLIGENCE: Low to average
ALIGNMENT: Chaotic evil
SIZE: L (9' tall)
LEVEL/X.P. VALUE:
    II | 130 + 5
    (IV | 250 + 6)

SAVES: 11.12.13.13.14

This aquatic ogre is generally faster, tougher, and fiercer than its land-based kin.
Aquatic ogres typically attack with a piercing spear (2-12 points) in a swimming charge at 1 to hit,
followed by melee with talons and teeth.

Camouflage: Aquatic ogres use their green coloration to hide (becoming effectively invisible 10-80% of the time, depending on terrain) and attack from cover,
surprising 4 in 6.

Aquatic ogres dwell in relatively shallow waters of 50-250 foot depth.
They lair in caves, often in association with scrags.
They can survive out of water for up to 2 hours,
so they sometimes raid the land.

Of 7-12 ogres, 1 will have 31-36 HP;
of 13-18, 2 will have 31-36 HP;
and of 19-24 ogres, 3 will have 31-36 hit points.

In the lair of a group of merrow there will be:
    1 chief, AC 3, 6+6 hit dice, +2 on damage
    2 sub-chiefs, AC 3, 5+5 hit dice, +1 on damage
    2-24 females, AC 5, 3+3 hit dice, 1-2/1-2/1-6 damage
    1-12 young, AC 6, 2+2 hit dice, 1-2/1-2/1-4 damage
    1 shaman, normal male or female

Aquatic ogres are able to speak Ogre as well as their own dialect. <noted in the DMG>

Description: Aquatic ogres are greenish and scaled with sloping shoulders.
Their necks are long and very thick.
They have huge mouths and undershot jaws. <note: I couldn't seem to get the definition of undershot from wiktionary>
Hands and feet are webbed.