EEL

Electric eels are found in warm fresh water. They will give off a jolt of electricity in a radius of 15-ft. 

Any creature within 5-ft of the eel takes 3-24 hit points damage; within 5-ft to 10-ft the jolt delivers 2-16 hit points damage, and between 10-ft and 15-ft the jolt delivers 1-8 hit points. The eel can do this but once per hour (six turns).

They are immune to electrical effects. Marine species are reported to be twice the size and do twice the damage.

Giant marine electric eels are found only in warm, relatively shallow salt waters, 30-150 feet deep being the common range. 

Athough these creatures move with relative lack of speed, they strike quickly, gaining a +1 on initiative. 

Once every turn, these creatures are able to release a charge of electricity. All creatures within a 5-foot radius of the individual eel so doing take 6-36 points of damage. Those within 5-10 feet take 4-24 points, and those within 10-15 feet take 2-12 points.

Unless such victims make a successful saving throw vs. paralysis, they will be stunned and helpless for a number of rounds equal to the points of damage sustained from electrical shock. Saving throws at 5-10 feet are made at +1, and at 10-15 feet at +2. Note that a successful save does not reduce damage by one-half, but merely negates stunning.

Giant eels are typically of the moray type. 

They have a nasty temper and teeth to match. 

Few (10%) are found in fresh water.

Weed eels are masters of camouflage, appearing as a patch of normal seaweed to any but a highly trained observer. 

Their bite is poisonous, and unless a saving throw is made the creature bitten will die.

They live in colonies, sharing food and home alike. Weed eel colonies consist of a network of small (six to eight inch diameter) holes which all lead to several 6-ft diameter tunnels, and the latter lead to a communal cave about 30-ft long, 20-ft wide, and 20-ft high. 

The eels use small stones, coins, gems, metal, etc. to floor this cave with. 

Colonies are found in both fresh and salt water, typically in water depths of 25-ft to 40-ft. 

If an attempt is made to enter any hole, the eel to whom it belongs will always strike with incredible speed. If eels note the entrance of foreign creatures, they will leave their holes to protect the cave where young are raised.