JiveBot and Codex are a meme pertaining to Shadowrun, created as a joke side storyline in the third Shadowrun Returns video game, Shadowrun Hong Kong.
On the Shadowland online forums, a location for Shadowrunners to swap stories online, Deckers occasionally create threads dedicated to poetry slams. These are invariably shut down by frustrated admins.
In one, early in the game, a user called Snozzbert creates an AI ESP to create poetry, which goes rogue and develops sentience. It then roams free on the net, even blowing a Hong Kong police sting with a poem for its own lulz and generally celebrating its freedom.
Eventually it meets with another rogue AI, called Codex, which leisurely pirated random data and money on the net and trolled companies releasing new software with accurate reviews. The two collaborated, becoming a lyric-strong Codex to the horror and amusement of the Decker community.
Shadowrun threads now have Anons calling themselves JiveBot or Codex, posting as their inspiration and getting into poetry battles.