He was born from the filth and muck covering GAIA after the Great Flood. Having nothing better to do, he was given the job of guarding the Oracle at Delphi to keep him out of mischief.
Knowing that LETO was pregnant by ZEUS, HERA planned one of her savage reprisals, and persuaded PYTHON to exact her revenge. LETO, managing to hide long enough to give birth to ARTEMIS and APOLLO, just had time to get APOLLO through to adulthood.
A mere four days later, he was a full-grown God and also proficient with a bow and arrow. Along came PYTHON, and APOLLO had no trouble chasing him into the Delphi temple for a good shafting.
To commemorate his success, APOLLO claimed the Delphic Oracle for himself, founded the Pythian Games and signed himself in the register as Apollo Pythian. We don’t know if his games included a flying circus.