Water Lash

You choose a source of water you can see within range and can manipulate it in one of the following ways:

• You form the water into the shape of a tentacle that makes an attack against one creature within range of the spell; on a hit the target takes 1d8 Cold Damage
  
  
• You Cause the water to jet out to a single target of your choice, the target makes a Strength saving throw or be knocked Prone, creatures Medium or larger have advantage on saving throws caused by this effect.
  
  

After either of these effects are resolved the water returns to it's source unless it is consumed by a creature or the environment. 

This spell's damage increases by 1d8 when you reach 5th level(2d8), 11th level(3d8), and 17th level(4d8)
Creature sizes with advantage to this spell's effect increase when you reach 5th(Large) 11th(Huge) and 17th(Gargantuan)