Are you still wanting ideas Krishnath? Just in case you are, here are a few:
Salt Spirit, Outsider or Fey or Elemental.
Appears as a figure carved from salt but can dissolve into a form (I suppose) that would be like a gaseous form. Probably give it dessication abilities.
Aquatic Angel
Angelic being with large fins instead of wings.
The Emerald Weapon, Construct probably (epic?)
Sorry but I had to get a little final fantasy reference in. This is a huge elemental construct-like creature that is spawned by a dying planet as a natural defence. It looks a bit like a robot, a bit like a golem, a bit like a frog, a bit like a fish and a bit like a submarine (not really but I don't know how to describe it

).
Paradise Fish,
A brightly multicoloured fish able to entrance creatures with it's scales and induce nitrogen gas euphoria (and damage) in creatures.
Styx Elemental
Evil water elemental with powers to remove people's memories.
Living Tsunami
A hugely powerful mischeivous aquatic gnome or pixie (small or tiny) that can transform into a gargantuan or colossal pulse of water (when angered) and has superior magical and elemental beings.
Reef Swarm
When fish turn nasty and get a hivemind.
Roc Ray
It's a really, really, really big ray...
Zarathan (might have got that wrong)
Did anyone ever convert the Turtle Island thing? (i'll find out it's in a core rule book now probably

)
I'll stop for now I think...