XD machine

Someone in a conversation who responds only with XD. Gets very annoying sometimes.
Similar to LOL machine and XD Boy. "XD Bot" might also be a good term for this thing.

Dude: I just fell into mud.!
XD machine: XD
Dude: hey, that's not funny!
XD machine: XD
Dude: Fuck you!
XD machine: XD
Dude: oh, that's that XD machine... screw that.
XD machine: XD