Number 10 of the Megaman X2 bosses is Crystal Snail. This boss is pathetically easy if you have Magnet Mine.
Now, normally I don't question the logic of SNES games for obvious reasons, but you have to wonder: Why would somebody build a snail reploid whose shell can be knocked off? I mean, wouldn't just armoring his body have been equally effective? No wonder Sigma's plans are always thwarted.