Apophis 99942 is a near-Earth asteroid that caused a brief period of concern in December 2004 because initial observations indicated a probability of up to 2.7% that it would strike the Earth in 2029.

Additional observations provided improved predictions that eliminated the possibility of an impact on Earth or the Moon in 2029. However, a possibility remained that during the 2029 close encounter with Earth, Apophis would pass through a gravitational keyhole, a small region no more than about 800 m (half a mile) wide, that would set up a future impact on April 13, 2036.

The diameter of Apophis is approximately 325 metres (1,066 ft). As of the December 29, 2012 observation arc, the probability of an April 13, 2036 impact is considered to be 1 in 11,000,000.

Apep or Apophis also spelled Apepi or Aapep) was an evil god in ancient Egyptian religion, the deification of darkness and chaos, and thus opponent of light and Ma'at (order/truth)

As the personification of all that was evil, Apep was seen as a giant snake/serpent, or occasionally as a dragon in later years, leading to such titles as Serpent from the Nile and Evil Lizard. Some elaborations even said that he stretched 16 yards in length and had a head made of flint.

April 2-0-2-9 the final time
The end my friend in not near
the hour in fact is quite here

It's a Friday the 13th of course
you won't live to see noon