'Splosion Man Easter Egg - The Maw

On level 3-17 once you have blasted yourself down the two crushers and killed the two scientists go to you left and fall down the hole once you have move to the right a little and you will notice some lab equipment one of them being a containment chamber within in The Maw 'Splode in front of it and you will get an amusing cut scene and an achievement for 15 Gamerscore