Yapping Maw
From A complete guide to Super Metroid speedrunning
If a Yapping Maw grabs (or even thinks about grabbing while in range of) Samus while she has a shinespark activated, the game can crash when she finishes the spark. This only occurs when no buttons are held during the shinespark or crash animation. Hold a button when sparking near a yapping maw! Note that the crash can happen in rooms without a Yapping Maw if the shinespark started from a room with a Yapping Maw.
Interestingly, holding any button will prevent the crash, even a button that's unassigned.