Banjo-Tooie

You can get this either in Jolly Roger's Lagoon during the submarine mini game you play. You can also get it in Terrydactyland by shooting 20 of the ulcers inside the dinosaur that swallows you. For the Jolly Roger way, you must play through the level and find the Glowbo for Wumba which is right under her Tent. This will allow you to turn into the Submarine. After that you must get to the underwater locker room and go into the black hole in the ocean floor. This will start the Mine mini game, simply shoot 20 of them. For the Terrydactyland way, you must get into the mountain. Use the springyshoes to launch yourself on the middle slim mountain piece. This is trigger a dinosaur to come out of the water and swallow you. He asks for your assistance to take care of his ulcers. Shoot 20 and the achievement is yours.