Haste

Haste is a status effect which increases mining and attack speed. Negative levels will decrease mining and attack speed, similar to Mining Fatigue.

Immune mobs
Most mobs are unaffected by Haste as they cannot mine blocks.

Instant mining
With Haste and Efficiency, it is possible to mine some blocks instantly. Below are listed the Efficency and Haste levels neccessary to instant-mine a block.