Ulitharid. Water+lobo? Yes. Arctic Octopus would be my 2nd choice.
As for flooding... it's virtually useless. Sure, it helps against creature spam like Fractal/FFQ/Boneyard/Pharaoh, but its very situational- it fails against basically everything else. Unless you know your opponent's deck is based on one of the above, you're probably not going to be relying on it.