Crashes after Mojang logo

Put the summary of the bug you're having here

What I expected to happen was...:
Should happen is the game finishes launching and brings up the main menu in game.

What actually happened was...:
After a few seconds on the mojang logo the game crashes.

Steps to Reproduce:
1. select snap shots enabled in the profile
2. hit the "Play" button
3. sit, drink some coffee, what it crash.