Found in Torvus Bog, the Spore Spawn clone known as Phlogus and its Dark World counterpart, Dark Phlogus have a funny, yet useless glitch. As per its normal actions, Phlogus will open its mouth, wait a second to give you a chance to shoot it before closing its mouth and expelling some sort of gas in all directions. If shot while its mouth is open, Phlogus will flip over and become a platform, no longer harmful to Samus (Dark Phlogus will also make a safe sone).
However, if you shoot it in the fraction of a second during which Phlogus is closing its mouth (I believe it does some sort of spinning motion right before), but hasn't quite finished yet. The result will be that Phlogus will flip over (and Dark Phlogus will make a safe zone) but will still hurt if you jump onto the platform area. Also, unlike normally, you won't get that knockback effect from being hurt, you will stand on Phlogus while constantly sustaining damage.
Useless, I know, but it's still fun to laugh at Retro's inability to keep small errors from appearing.