The Giant Galapagos Tortoise needs very strong, sharp, beak like outer mouth parts as it's main food source consists of tough clumps of grass and other vegetation which it tears up and crushes in it's mouth before swallowing. It also feeds on a particular type of succulent Cactus which grows in the harsh environments of the Galapagos lava fields and rocky areas. The froth bubbles around the eye keeps the pupil clean.