Blasts Conor McGregor As 'Piece of S***'

“I can make you rich,” McGregor told Rafael dos Anjos at the UFC 197 news conference -- explaining, "I change your bum life; you fight, it’s a celebration. When you sign to fight me, it’s a celebration. You ring back home, you ring your wife, ‘Baby, we’ve done it. We’re rich, baby. Conor McGregor made us rich, break out the red panties. We’re rich, baby.'"

So, when Conor saw Usman using a similar line (replacing red with green because of the color of the Nigerian flag), McGregor called him out on social media.

"Am I tripping or is this jackass always at this? Everything I say," Conor tweeted.

Well, Usman's manager saw the tweet and decided to respond -- aggressively.

"Kamaru Usman is a great…