We've all been there. You've just taken your first steps into supervillainy; you've robbed a few banks, built a doomsday device or two and finally got just the right number of spikes on your costume. Things are looking pretty sweet for you as you get ready to unleash your army of mutant robosharks on the world, but then who should appear from out of the blue? It's only Superman himself.
"Well this is a bust" you think to yourself as your army is dismantled in a matter of minutes and you prepare yourself for the inevitable punch to the jaw. However, fear not potential villains for all is not yet lost.
While Superman's powers may make him seem invincible, he actually has a number of weaknesses that have been showcased in the comics over the decades (and luckily that number is at least 10 or you'd be reading about how too much cheese probably makes the Man of Steel a bit gassy).
Some may be obvious to anyone who hasn't been living under a green radioactive rock, others are so obscure that only the most die-hard fans have heard of them. Either way, each one is a surefire way of getting rid of the Last Son of Krypton so that you can get on with all the terrible crimes you have planned.
Like stealing 40 cakes.
Let's start by getting the obvious one out of the way.
When exposed to the glowing green chunks of his former home planet, Superman is greatly weakened and long-term exposure can even result in his death. It is Kal-El's greatest weakness, that and the fact that the universe seems to hate him enough to make sure every single lump of kryptonite winds up on Earth.
Over the years, it has been used by everyone from Metallo (who uses it to power his robot body), to the Kryptonite Man. Even Batman keeps a sliver of the stuff, just in case Superman were to ever go rogue.
Most famously though, it is used by Lex Luthor to power his Anti-Superman Battle Armour. He also used to wear a ring made of kryptonite, but that had the slightly inconvenient side-effect of giving him cancer.
There are also various other forms of kryptonite for when writers are feeling lazy. There's red kryptonite which causes Kryptonians to lose all inhibitions, gold kryptonite which can completely remove Superman's powers and a whole host of other weird and wacky variations. One Silver Age story even featured red-green kryptonite, which inexplicably caused Superman to grow an eye in the back of his head.