It uses whatever graphics are in the area. The Mr I sprites must be grouped with the explosion sprites, and since he's currently active (and wasn't intended to with Bowser) the game uses duplicates of his graphics by mistake.
Where is @SwankyBox? Edit: Also, in SM64, you should be able to collect multiple stars at once, besides 100 coin stars and other stars that don't kick you out of the map, except the one(s) you are aiming for. For example, this challenge would net you 8 stars + 1 key, and the key would kick you out regardless; so, just yeet the friggin' bosses, pick up the 8 stars, grab your key, and get outta dodge.
@@boredyoutuber9275 You're telling me bosses with some logic, reused textures and rudimentary models occupy more memory than the aggressive amounts of stage models or textures...?