If may seem as though Bill Belichick is always a grumpy, curmudgeonly, man. More often than not, he gives that appearance in public. But sometimes, he goes the other way. We got a glimpse into one of those times on Monday, the 66th birthday of the New England Patriots coach.

In an old video, then Patriots receiver Randy Moss invited Belichick to come to a Halloween Party. Moss clearly assumed that it was not the coach’s forte. The conversation between the two was entertaining enough. The end of the video, when Belichick showed up to the party, has to be seen to be believed.

No, you were not slipped any pills in your food. That is Belichick dressed as a pirate and rollerblading around. He certainly owned the night.

Given that Belichick hardly smiles after winning a Super Bowl, we’re guessing there’s not many videos like this one out there. Though, if you know of any others, please let us know.