Tanktup

Tanktup is a large, brown turtle found in Bubblegloop Swamp in Banjo-Kazooie. He complains about having cold, numb feet which Banjo and Kazooie can remedy by Beak Busting his flippers, shocking him into pulling them inside his shell. He thanks them afterwards and opens his mouth to cough up a Jiggy, also allowing access inside his shell which you can travel into to find Tiptup and his choir.

There is a pair of Wading Boots on his shell which Banjo can use to grab the orange Jinjo.

A wooden model of Tanktup can be seen in Banjo-Kazooie: Nuts & Bolts in Banjoland, but it is mentioned that Tanktup disappeared after the events of Banjo-Kazooie and his current location is unknown. He also appears in the Banjo-Kazooie theme for the player's XBOX 360.

Banjoland Info
"Banjo and Kazooie could enter Tanktup in Bubblegloop Swamp once they'd warmed his feet and he'd barfed up a Jiggy. This is just a wooden effigy, as Tanktup's whereabouts are currently unknown."