Giant catfish

Giant catfish were naturally occurring mutations of the ordinary catfish.

"Nogah's finely scaled, webbed hands pulled sharply on the reins that stretched down into the murk. Some of the cords were attached to the whisker-like barbels of the beast pulling the sea coach: a catfish the size of a small whale."

Description
These giant fish were often of chalky-white coloration or grayish brown. Their sizes usually varied from for the white-colored breed to  for the brown.

Behavior
These creatures were known to display aggressive behavior and thus they would often and attempt to swallow any creature that was suitably small enough despite their usual diet. Because of this, they often posed a threat to races of short statue, such as dwarves, gnomes, and halflings.

Biology
Like their normal-sized cousins, giant catfish had many spiny, long tentacle-like feelers on each side of their mouths. Some referred to these as "whiskers." The whiskers on giant catfish secreted a strong toxin poison.

Combat
When hunting or provoked into combat, a catfish immediately went for a bite or attempted to swallow it whole if possible. They sometimes used their feelers as weapons by whipping their heads back and forth or side to side.

History
Around 1396 DR, giant catfish were often tamed by the kuo-toa of the Sea of Fallen Stars, as evidenced by the gargantuan nautilus shell carriage pulled by giant catfish that belonged to Nogah, the senior whip of Blibdoolpoolp.

Sub-Species
An underground type of giant catfish that lived in the tunnels of the Underdark. In instances when this species made its way to the surface, they became top predators of the surrounding area.
 * Stalking catfish:

Ecology
Due to being territorial, giant catfish were often encountered alone, although groups weren't unheard of.

Diet
Giant catfish were resilient omnivores whose diet was primarily bottom-feeding scavenging. Because of these dietary habits, giant catfish needed a large area in order to find enough food to survive.

Habitats
Giant catfish were commonly found living in large rivers, or lakes that such rivers fed into, in climates that ranged from tropical to temperate. They typically dwelled within the cool dark muck of such aquatic environments. On Toril they were particularly known to be encountered in the River Ashaba and Dragon Reach.

Appearances

 * Plague of Spells