Logan Paul's spittin' on that thang in WWE ... performing a celebration inspired by the "Hawk Tuah" girl mid-bout -- and, it's got the internet in a frenzy.
The YouTube star turned pro wrestler pulled up to "WWE SmackDown" Friday night in Madison Square Garden and faced off with LA Knight and Santos Escobar in a threeway battle ... and, after failing to pin Escobar, he pulled his head back and spat out the viral phrase.