How do you beat the fish?

It looks complicated, but it's really very simple.
First, that big salmon will poke his head out of
the lake and spit at you. Duck or jump. Then he'll
sink back into the lake. Quickly, with your Frezze
Wand, make a bridge on top of the lake. If you 
manage to do it from one end of the lake to the
other, you'll succeed and make the fish surrender.
Then you can grab the Ice Cube Wand, save Goofy 
and move on to the level.

by Michael Harrington