His name is ะต Joseph Poolpo.
This man is unique with this — he can sing in three voices, simultaneously (beat box, but in three voices!).
Two years ago I’ve found a video with him; the video was on YouTube and later I have found that it is deleted (possibly a problem with copyright).
But these days, by accident, I have discovered another recording with him:
I hope that YouTube won’t delete the video this time — watch it, while it is possible! :-)