What happened in the end credits of Ant-Man and the Wasp?

What was that at the end of Ant-Man and the Wasp?

July 7, 2018 Dug (Wugmanmax) 0

This post contains MAJOR spoilers for everything in the previous Marvel movies, in case you care.
Ant-Man and the Wasp has arrived in cinemas bringing the same fun mix of comedy and action as the first! It, of course, has after-credits codas.  
Seriously, if you aren’t caught up in the MCU series, you probably don’t want to keep reading.