Shadowy figures spiking from entities. (Mobs, Blocks, etc)

While playing, sometimes Entities would have long spiking shadows on them. Another bug I found, was at times the screen would go on many colors in a certain direction, and the only way to combat it was to sleep/ restart the game. One facing in the new version is the lack of even getting on to Minecraft in the first place, freezing upon starting the game.