Dr. mundo is a fun character even though he is quite hard to play in 5x5.
he is easier and more fun in 3x3.

with mundo never go mid always top or bottom.
the reason i said he is hard to play in 5x5 is because the enemy team is more than likely going to have an ignite.mundo is extremely voneralble to ignite!! u can build him kind of tanky
which is good but i like to use him to chase people because of his outrageous movement speed.
so i tend to build him more of a assasin. i know it is weird but this works.
i like to take flash and ignite for my summoner spells. ignite u can just deal more damage
from a length away and flash i use it to jump in to get a kill and i also use it to get out of bad situations.you need to start to max out infected cleaver once you have gotten the rest of your abilitys.

get a ruby crystal first for the health because all of mundos moves cost health.
and i also take a couple heath pots to stay and help my lane out longer
next i get a regrowth pendent to alow me to stay in lane longer and replace the health pots.
i also get murcery tread to help out with my already outrageous speed.
i get madreds to help do a little more damage to enemy champions.
next i get a leviathan which stacks every time u level up.
if the enemy can pretty much ignore you i usually get an infinity edge to ensure that they are afraid to come near u in a battle.

hope you enjoyed my build.
if you are a mundo freak would love to hear any tips because there is always room for improvement.
leave a comment below thank you for reading my build
ggog