I love how 
is more and more relevant and I giggle more than I should every single time it pops up in a thread lately (which is very often now). Death to the treat empire. At least it will be hilarious while it collapses.
Just throwing ideas out here, as I can't identify any specific cause. Maybe the quick link isn't the right size for the chain? Maybe it's not fully snapped together? You should test the individual pivots on the link and see if they're stiff and need to break in, that could be another cause.
Could your derailleur be between gears? Have you tried dialing it in? Check out Park Tool's repair videos on YouTube, very in depth and helpful for learning bike maintenance.
this dude's definitely banging the doll
Come and see