Where is shroomish in Pokepark wii?

Do you know that lake where Magikarp is in? When you're there, look at the map for the rounded area (Bottom Right Corner I think) and smash all three crates with your head. It will be hiding inside one of them, but when you look for it, Shroomish won't be there, so turn around and run back the way you came, and there he is. Don't miss him like I did.