The animan which will never die.

Well human are very vulnerable creature and are susceptible to lot many things - (most of which are already mentioned in other answers).

But not this fella Tardigrade

Tardigrades are one of the most resilient animals known.Individual species of tardigrades can survive extreme conditions that would be rapidly fatal to nearly all other known life forms, including complete global mass extinction events due to astrophysical events, such as supernovae, gamma-ray bursts, large asteroid impacts, or passing-by stars.