As a star, the sun is so big that it can accommodate 13 lakh earths. Now imagine a star that is around a hundred times larger than the sun and outshines the sun five million times.
Such massive stars produce and distribute a large amount of elements vital for formation of life when they eventually explode as supernovae. Unfortunately, these hypergiants are extremely rare as their size makes them unstable.
According to Nasa, the lone example of such a star until recent times, which has not exploded, was Eta Carinae.