Deontay Wilder: Tyson Fury Sings Horribly ... And I'm Gonna Beat The Hell Outta Him

WBC heavyweight king Deontay Wilder is calling out new champ Tyson Fury ... saying his post fight serenade to his wife was total EAR TRASH ... and promising to REARRANGE HIS FACE.

Wilder checked in with the crew on the "TMZ Sports" show on FS1 -- and told us he's gonna beat Fury so badly, his wife is gonna wanna leave him.

"I'm gonna destroy him."

The smack talk is great ... Wilder even drags Fury's mom into the mix -- good times.