Spelunky

for those looking for an extremely simple and easy way to get this one:

Simply play co-op and make your 2nd controller carry around any damsels you find. You can carry around your partner even while they're carrying a damsel, if you're going it alone. Once you encounter a shrine to Kali you simply sacrifice the damsel AND your friend! Alternatively, after sacrificing your friend, if you can't find a damsel but CAN manage to kill yourself and land your body on the shrine, that will work as well!

Kapala and Achievement = Yours. your friend gets the achievement, too! (assuming they've got their own profile)

Shrines are pretty hard to miss; they're blood-drenched altars below a large deity, and if you blow one up you'll spawn a load of spiders.

I guarantee you'll find a Kali shrine and damsel on the same map without having to leave the mines if you're patient/lucky enough.

TO THOSE UNAWARE: YOU USE THE KAPALA TO COLLECT BLOOD. Collected blood will add up, eventually filling the cup and giving you +1 heart. This can be done infinitely, as long as you can find blood!

It's also worth noting that sacrifices to Kali stack, so if you wanted to get this one in a legitimate playthrough you'd just want to make sure to sacrifice anything and everything (anything stunnable) at every opportunity and you'll get your Kapala soon enough.

Happy spelunking!

Kali is the Goddess of Death, which you will encounter pretty early in the game. She is represented by a gigantic statue with a bloody altar beneath her. To get this achievement, you will need 16 Favor with Kali, which is gained by sacrificing stunned or dead bodies by placing them on the altar. You can see a list of points here:
http://spelunky.wikia.com/wiki/Altar

I suggest going for this in the Jungle. Try to get sacrifice two stunned Cavemen for 4 points (be careful that they don't un-stun in your arms), then sacrifice the Damsel afterwards.

Another easy tactic to get it is to simply sacrifice two Damsels. This leaves you with less health than you would have with the tactic above, but that might not pose a problem if you are solely going for this achievement, in which case sacrificing two Damsels at the first two Altars you see would be the best option.

Another way to get it easily when you have only one controller :)
You need to cumulate 16 points.

- Find a stage with an Altar.
- Find the damsel and sacrifice her (12 points).
- Find a rock and take it.
- Try to launch the rock on a wall. The rock must bounce and knock you out on the Alter to sacrifice yourself :D

Watch the video ;)