When you get to the Gassy Galbos hanging out on their icy ledges, drop down to where there is a door and then two ice columns. Break them open to find doors in which Rick and Coo hidden in these rooms. Take Coo as your helper, and inhale a Gassy for some fire power. Just keep going, until you reach a room full of ice. Break through it all, until you come to a door with two plants. You need to get in here, and without Coo and Fire you can't. So go through the door to find some more ice blocks to break through.. and ChuChu!

First, use Chu Chu's hot air balloon power to break the ice blocks going up, and Coo's power going down. Keep switching until you can reach the next door. You'll then find the Snail's shell, and also get to fight another mini-boss. Continue through the level to bring back the Shell's portable house. Awwww.