The Wild Kratts are having a picnic when a seagull steals one of their creature power discs and drops it into the ocean. The Kratt Bros dive in to retrieve the disc and encounter an enormous lobster. Could this be the "Last Largest Lobster"? Martin and Chris begin to follow him to investigate the life of a lobster. But there's someone else on the lobster's trail. It's Chef Gourmand Gaston, who plans to catch him and "cook him up". It's up to Martin and Chris to stop Gourmand and save "the last largest lobster".