In contrast, it also needs to be in a place where some of the water it produces can run off, or it wiil create enough water pressure to crush itself.
Splanxties are mischievous water-dwelling creatures related, it is said, to both nixies and leprechauns.
They live in swiftmoving bodies of water (mountain streams, rapids, waterfalls, and so on) and never move far from such torrents.
They are never surprised and, while in contact with flowing water, can hide so as to be 50% undetectable (cf. thief's hide in shadows ability).
Splanxties carry fine, tiny bows (similar to those of pixies). Their arrows are all +4 to hit, cause 1-3 hit points of damage and a loss of 1 point of strength for 1-4 hours. These bows and arrows can only be used by splanxties.
Once per day, a splanxty can create an illusion with both audible and visual components which lasts without concentration for d6+10 rounds or until magically dispelled.
Splanxties are also able to throw their voices (cf. ventriloquism spell) and to imitate the speech of all humans and demihumans (although they are only able to speak in the common tongue).
A splanxty can animate small quantities of water (up to 60 feet away) to create irritating splashes, jets and so forth. Alternatively, the jets can be made to strike out at creatures within 5 feet of the torrent. Up to two attacks per round can be made in this way, and thc splanxty may perform other actions at the same time. Each jet has a THAC0 of 16, and causes 1 hit point of damage. Striking at the water with weapons will not affect these attacks in any way.
Once every 3 rounds a splanxty can move instantaneously between any two points joined by flowing water (up to 100 feet apart).

(Dungeons & Dragons)
Rulebook featuring "high magic" options, including a host of new spells.