Kawhi Leonard Finally Laughs and It's Weird

If you're wondering why Kawhi Leonard is trending on Twitter today ... it's because his laugh is freaking some people out.

The NBA star was officially introduced by the Toronto Raptors at media day on Monday -- when the usually serious dude broke out in laughter.

First, people aren't used to seeing Kawhi laugh ... so there's that.

Second, it was a little weird and now people are comparing him to a robot.