Super Metroid
Found only in Norfair, Magdollite's are thin, lava-form creatures that stretch themselves into a tall column of magma, usually equal in height to thing it's attacking, like Samus. It will then shoot fireballs at it's opponent, before falling back into the lava.
 Metroid: Other M
The appearance of Magdollites changed considerably in Metroid: Other M, becoming humanoid in looks though still attacking similarly. When destroyed, they now roar and sink into the lava in flames. They appear consistently and only throughout the Pyrosphere, and only in lakes or pools of lava.
In the Geothermal Power Plant, a Magdollite inadvertently saves Anthony Higgs' life when he is knocked by Ridley to the lava below. The Magdollite rises up from the lava to attack, and Anthony uses his Freeze Gun to stop it in its tracks and render it as a platform for him to use, saving him from certain demise.