Clapper the Seal is an unplayable and rare animal friend that first appeared in Donkey Kong Country 2: Diddy's Kong Quest and Donkey Kong Land 2. He is a seal that is found laying down on the ground, in front of water. Clapper has a very unique ability to either temporarily cool down pools of lava into regular, swimmable water or freeze bodies of water when jumped on. Clapper will then clap to signify the change, hence his name.
Even with those two very useful abilities, he is only found in two levels: "Lava Lagoon" and "Clapper's Cavern". Clapper, like most Animal Buddies, has an entire level named after him. In the two levels he appears in, he can be oddly found in several locations in the level. This is because these levels consist of lava and water respectively, and Clapper's cooling and freezing powers (respectively used) are needed throughout the whole level. Even so, the only other animal buddy with more than one appearance in a single level is Enguarde in Coral Capers.
In Lava Lagoon, his cooling power was used to safely swim to the next point of walkable area in the level, but underwater enemies will be unaffected. As the water rises, Kongs had to race to Clapper in order to keep themselves safe, as contact with the lava is instant death (often seen in other platforming games). In Clapper's Cavern, where he was also critical to navigate the level safely, Clapper froze the water, which had a hungry Snapjaw in it. Diddy and Dixie had to cross the icy water to the next land area, away from the Snapjaw. Zingers were obstacles while crossing the ice.