Wave element can be used to combine Avalanche, Beach, Sound, and Surfer in Little Alchemy 2. There are several ways to make Wave, some of them are complicated. We have figured out the easiest way, you need just 10 steps. After you created Cloud, Storm, and Lake, you could combine Wave easily. Check out the detailed walkthrough and try it yourself.
Earth + Earth = Land
Earth + Land = Continent
Continent + Continent = Planet
Air + Planet = Atmosphere
Water + Atmosphere = Cloud
Cloud + Cloud = Storm
Water + Water = Puddle
Water + Puddle = Pond
Water + Pond = Lake
Storm + Lake = Wave