Conor McGregor is arguably one of the biggest stars in the UFC to date, though he might be past his prime as a fighter. To feature in the top five pay-per-views in the promotion's history, the Irishman had to do his bit to stay relevant.McGregor, apart from being one of the best athletes to have ever played the sport, is also famous for his trash talk which seems to come to him naturally. Over the course of the years, 'The Notorious One' has managed to engage his opponents in battles outside the ring and even dealt considerable damage on certain occasions.In light of Conor McGregor's ongoing feud with Dustin Poirier, let's take a look at other instances when the Irishman was engaged in Twitter wars:#4 Conor McGregor vs. Floyd MayweatherConor McGregor had several exchanges with Floyd Mayweather ahead of their boxing bout inside the T-Mobile Arena in Las Vegas in 2017. While McGregor lost the bout via TKO in the 10th round, he was persistent with his efforts on another front.Mayweather took a jibe at McGregor by posting a picture of himself punching the Irishman during their bout. To follow up, the legendary boxer added a video of himself menacingly looking at the camera while entering the Octagon.Not one to back down, Conor McGregor replied in typical fashion over Twitter."Hahahaha very good. Keep up the good work my son. Yours sincerely, Senior."Hahahaha very good. Keep up the good work my son. Yours sincerely, Senior. https://t.co/Qk3U69isTS— Conor McGregor (@TheNotoriousMMA) January 30, 2018Immediately following it up was another short and concise post from Conor McGregor which resembled his chant for the Mayweather fight. Sparing Floyd Mayweather's father and uncle, McGregor further wrote:"F**k the Mayweathers, except Senior and Roger. There is no peace here kid. Step up or step down."Fuck the Mayweathers, except Senior and Roger. There is no peace here kid. Step up or step down.— Conor McGregor (@TheNotoriousMMA) August 29, 2018#3 Conor McGregor vs. Nate DiazConor McGregor and Nate Diaz sport one of the fiercest rivalries in the history of the UFC. The two have squared off against each other on two occasions - at UFC 196 and UFC 202 - with one fight going each of their way.In their most recent Twitter war, Conor McGregor started things off by replying to a fan's comment about the "McGregor belt." Referring to the BMF title associated with Diaz, McGregor wrote:“Isn’t that crazy! Who’s the real bad motherfucker anyway? Went up two weight divisions on a weeks notice to fight him for that fight. No hesitation. Straight onto my jet. In thru the side door. Surprise, surprise,”Isn’t that crazy! Who’s the real bad motherfucker anyway ? Went up two weight divisions on a weeks notice to fight him for that fight. No hesitation. Straight onto my jet. In thru the side door. Surprise, surprise https://t.co/ku9NtjAsBT— Conor McGregor (@TheNotoriousMMA) March 31, 2021This immediately caught the attention of Nate Diaz and the Stockton native replied:“Who went up two weight classes in half a day notice no hesitation and not promotion about it just did it cause I ain’t no bitch how’s that Conor fuck you. Whatever you think you did already been done by a real G Try not to get finished again.”Who went up two weight classes in half a day notice no hesitation and not promotion about it just did it cause I ain’t no bitch how’s that Conor fuck u Whatever u think u did already been done by a real G Try not to get finished agaaaain pic.twitter.com/eA5zK7Ffp3— Nathan Diaz (@NateDiaz209) March 31, 2021The duo embarked on a full fledged war after this which would go on for a while.What in the Facebook prelims is this shit ? Who the fuck is Rory Mark ham ? 177? 😂😂😂— Conor McGregor (@TheNotoriousMMA) March 31, 2021Don’t forget Dustin fucked u up But he’s scared of me You are both some bitches And I slapped kabob he was scared with no counter And he owned you so who’s the real king Me bitch that’s whoKing Nate dog 👑— Nathan Diaz (@NateDiaz209) March 31, 2021#2 Conor McGregor vs. Khabib Nurmagomedov and Ali AbdelazizConor McGregor and Khabib Nurmagomedov gave us one of the greatest sporting events in recent times when they met for the UFC lightweight title at UFC 229. While Khabib decisively won the contest via fourth round submission, the Twitter war between the two still seems to be unresolved.Conor McGregor took a jibe at fellow lightweights through a Twitter post from May, 2020 that read:"Without me this whole ship sink. Never forget that! #BigYachtsy"Without me this whole ship sink. Never forget that! #BigYachtsy— Conor McGregor (@TheNotoriousMMA) May 13, 2020Like on previous occasions, Khabib's manager Ali Abdelaziz was quick to jump into the fray. Abdelziz responded with a Tweet featuring footage of Conor McGregor getting battered by Khabib on the ground at UFC 229.Just like that 😂 @TeamKhabib https://t.co/qSx7XFY3cp pic.twitter.com/pjeDX2q6k2— Ali Abdelaziz (@AliAbdelaziz00) May 13, 2020The day before, McGregor had directly targeted Khabib Nurmagomedov via another post on Twitter. Accusing Khabib of avoiding Tony Ferguson, McGregor wrote:"Khabib you absolute embarrassment. Scurrying, hiding rat as usual. As I have said many times. As has been seen many times. Through the pane of glass it was confirmed what was always known. “No comment” lol. An embarrassment to real fighting."Khabib you absolute embarrassment. Scurrying, hiding rat as usual. As I have said many times. As has been seen many times. Through the pane of glass it was confirmed what was always known. “No comment” lol. An embarrassment to real fighting.— Conor McGregor (@TheNotoriousMMA) May 11, 2020The Dagestani fighter responded by asking McGregor to "not be fake" and added another image of himself dominating Conor on the ground.Yes, we remember you, you was so nice that night, be same, don’t be fake. pic.twitter.com/SOcLb5jjKX— khabib nurmagomedov (@TeamKhabib) May 11, 2020#1 Conor McGregor vs. Dustin PoirierIn his most recent battle over Twitter, Conor McGregor has jeopardized his much anticipated trilogy fight against Dustin Poirier. The banter started when Poirier called McGregor out for not donating $500,000 to his charity, The Good Fight Foundation, which McGregor had promised in the case of Poirier defeating him at UFC 257.That's a fun prediction! @TheNotoriousMMA you also predicted a donation to my foundation and you and your team stopped responding after the fight in January. See you soon. July 10th Paid In Full!— The Diamond (@DustinPoirier) April 11, 2021Responding to Poirier, McGregor said:"A donation, not a debt. We’ve been awaiting the plans for the money that never came. I do with all my donations. Know where it’s going dot for dot. Otherwise it goes walking. As is the case with a lot of these foundations, sadly. You took the McG over the belt shows I was right."A donation, not a debt. We’ve been awaiting the plans for the money that never came. I do with all my donations. Know where it’s going dot for dot. Otherwise it goes walking. As is the case with a lot of these foundations, sadly. You took the McG over the belt shows I was right.— Conor McGregor (@TheNotoriousMMA) April 12, 2021Conor McGregor would finally counter with a few more obscenities before suggesting that the fight is off.You’re ripped you inbred hillbilly. Why do you wink with your ears? You fucking brain dead hillbilly. 500k with no plan in place. Ye hang tight. Fool. You must be new to money. The fight is off btw. I’m going to fight someone else on the 10th. Good luck on your old contract kid.— Conor McGregor (@TheNotoriousMMA) April 12, 2021