great guide and build, very well explained +1

Frozen Mallet might seem as overkill at first glance, but with some practice and combined with Mundo's inherent utility it allows you to (almost) permanently slow two targets by 40%. If used on the same target, I agree with you, it's passive is nearly useless. Even though the slows stack, diminishing returns will reduce the nett. slow to roughly 65% of your target's total movement speed. Still a considerable increase over 40%, but completely unneccesary.

I disagree on Rylai's Scepter. Although it allows you to slow everything around you continuously, the only thing Mundo benefits from is the health it gives. Frozen Mallet and Rylai's Crystal Scepter cost 3250 and 3105 gold respectively, so about the same. Mallet also provides +200 health over the Scepter and with my runes (and in general) I find the +20 attack damage more useful than the 15% area slow.

Besides that, I think Frozen Mallet's only suitable alternative could be Warmog's Armor, which is also in most of my builds.

I chose to pass up Guardian Angel for items that increase survivability BEFORE death, because in my experience, if you die with this build, you're doing something wrong. I've walked away from many 1v5's without even getting close to death, so I believe Guardian Angel is not needed on Mundo. Its passive at least. The item is too expensive to buy it just for the stats.

I put Banshee's Veil in the anti-AP build with some reluctance. I think with the core build assembled and about 4k health with 70% CC reduction you couldn't care less about one spell hitting you. I'm going to find a suitable alternative for the build, but I doubt you will ever complete that last item anyway against a full AP team. :)

Thanks very much for your reply, I hope this answer clarifies my intentions for Mundo a little, I'm looking forward to your reaction.

ok frozen mallet on mundo is just useless . he hits to slow plus i think the best choise istead is relais scepter . plus i think mundo as a tank is better all the time to use his abilities and focus on them . you can take and a gurdian angel. last instead of passive of the banshees you can take the cleance summoner spell