This makes me both very happy and slightly afraid at the same time.
In a very candid behind the scenes video, actor/musician Rory McCann who plays the meta grumpy The Hound on Game of Thrones, broke out his guitar from behind the trailer window and began singing a super-trippy version of “Yellow Bird”. Actor Kristofer Hivju, who plays Tormund Giantsbane, joined in with silly background vocals. Both attributed this spontaneous outburst to that feeling “when you’ve had too much trailer time!”.
(Source: Laughing Squid)