Pros: He has strong poke.
Cons:
No CC ( beyond a skillshot slow ) can't peel. Can't initiate. Does barely any damage despite his steroids. Pretty shitty passive, honestly. It's k in lane, but you'd never notice it if you didn't know about it already. Ultimate is entirely countered by ignite.
Why should you ever pick Mundo? Why would you pick a tank for their poke when they sacrifice literally everything else that makes them a tank?
Vicvictorw7 votesWhat he pleases.
Professor Ward3 votesi do agree that in 100% of cases there is a better top lane choice than mundo
Godaren2 votesHis damage is actually really high his w is way better than shyvanas w and he is one of the best pure tanks in the game but yeah right now he just gets outshined by gnar and maokai who bring more cc to fights.
Sorgklaan2 votes[{quoted}](name=Crazy for Jinx,realm=NA,application-id=3ErqAdtq,discussion-id=oJIQKvEK,comment-id=0000,timestamp=2015-08-07T04:02:02.589+0000)
His damage is actually really high his w is way better than shyvanas w and he is one of the best pure tanks in the game but yeah right now he just gets outshined by gnar and maokai who bring more cc to fights.
Singed is probably the closest champion like him, and singed is SO much better.
Hasztalan22 votes[{quoted}](name=Crazy for Jinx,realm=NA,application-id=3ErqAdtq,discussion-id=oJIQKvEK,comment-id=0000,timestamp=2015-08-07T04:02:02.589+0000)
His damage is actually really high his w is way better than shyvanas w and he is one of the best pure tanks in the game but yeah right now he just gets outshined by gnar and maokai who bring more cc to fights.
He is an offtank mind you....
Austinodood1 votesHis damage output for how tanky he is is actually super high. There are some matches that I play as Mundo and have the most damage taken, in addition to the most damage dealt.
Sorgklaan2 votesHis damage output for how tanky he is is actually super high. There are some matches that I play as Mundo and have the most damage taken, in addition to the most damage dealt.
Yeah, you can do damage with him, but it tends to be spread out over so much time, and the fact that you need to be injured for your AD steroid to work means most of the time you are just completely ignored while the enemy team slaughters your allies and you can't do shit about it.
X SkeletonCandy1 votesIf Mundo isn't taken care of early on in a teamfight, he's going to be doing stupid amounts of damage.
Never doubt Mundo.
ModKnightsKemplar1 votesI agree with others here. His damage to a backline can be outrageous if he can get there. He can't be your main initiation, but he is still a threat.
Trebbi1 votesBecause at 1 point he could just sit on people and they would just die and tank towers for days.
OhthePiplup1 votesHe goes where he pleases
vonGroopah1 votesMundo isn't a tank, he's a fighter. It's just very confusing because he's a fighter whose scaling is so crammed into health and magic pen that you look at him look at his build and go "wow he's tanky with a slow". The thing is he offers no protection to his team: his power is very selfish (compare this to Maokai). Imagine line, and on this line are sustain-based fighters (from interactive to non interactive). On the very right end is Mundo and Volibear, whose sustain is very non-interactive, while Aatrox & Xin Zhao are in the middle and Garen & Warwick are on the very left. His weaknesses are glaringly obvious and it's bad feeling to watch you team die as you're wiggling around on the battlefield with your dick in your hand boogeymanning the enemy backline
Seekêr1 votesBut....Mundo goes where mundo pleases 
DrinkurMilkshake1 votesHis terrible win rate, inability to be an effective jungler after season 2, nerfs to all his core items, nerf to his Q, adding damage % of current health in many new champs and reworks, new items being generally incompatible with him...
Riot has given up on Mundo entirely. He's among the worse top lane choices right now. I see them buffing Lee Sin / Shen because they have the mobility to make big plays while ignoring Mundo (despite Mundo having a consistently lower win rate than either).
Lugg1 votesMundo is a great tank against AP heavy teams. A cinderhulk Mundo basically never dies. That is what he is picked for.
He has great damage with an AoE and since his Q at max rank is 25% health damage, he has built in tenacity, AD steriod, and a low CD ult that makes it take so long to kill him, it's not worth it. I have literally chased an entire team down mid lane back to their base by myself as Mundo.
Only Play Darius1 votesHe facetanks all the damage and tries to get people to damage themselves trying to get rid of him. Which is why removing Force of Nature (AP Thornmail) hurt him so much.
stealthfox941 votesStop saying Mundo goes where he pleases.
Elkington1 votesHe used to be a late game monster back when armor was good and %hp damage/grievous wounds were nowhere near as prominent. Only a small handful of champions could kill him late game (talking way back in S2).
Now with all the mobility and utility champs have, coupled with everyone having %hp damage, Mundo needs something else in order to compete I feel. Nearly anyone can deal with Mundo now, even late game. He just can't soak damage like he used to.
His kit is very outdated, but he can still work if you're good at him. It might be time to give Mundo either %damage reduction or more damage on his W. I mean, Maokai and Alistar get %reduction and they offer a lot more than Mundo does at all phases of the game.
The longer Mundo stays alive, the longer he can deal damage and the more of a threat he becomes.
Mundology1 votesCAN WE BUFF MUNDO??
Erockandroll1 votesIt's hard to compare Mundo to Tanks, (and even some Juggernauts) because he has a unique source of Tankyness. And that Source is his Regen. This obviously makes him better in extended trades than all ins.
Personally, I wouldn't think tanks should survive if focused by the enemy team. But if Mundo is getting soloed, then I would say he's too weak.
In Mundo's case, His Tankyness is his regen, so that should be looked at. Perhaps you could make his ult remove Grievous wounds on cast.