It started when he told Apollo Crews to "go back to Ring of Honor" during a match (Crews, of course, was never in Ring of Honor) last year. It continued just days ago when he responded to Austin Aries making his debut in NXT with this:
Then, he bodied Corey Graves:
@WWEGraves that coming from the guy who's last two pics on IG are work out shots— Baron Corbin (@BaronCorbinWWE) March 4, 2016
Banter Corbin is everything.