On a fresh load of the game if you look at far away grass from a non perpendicular way, you will see what looks like vines on the block, but if you adjust the mipmap levels, it will reload the game, and be fixed for the remainder of gameplay. As soon as you hard restart the game, you will see it again.

1. Load game
2. Look at grass blocks sideways

How to temporalily fix

1. Adjust mipmap levels
2. Fixed