Finally found a jungler that fits my playstyle (I think)

I've been struggling with jungling for awhile. It's definitely my weakest position now that I've learned to last hit relatively well. I still struggle with being aggressive as an ADC but if I take a hyper carry (like Vayne) and a sustain support like Sona that can just harass but not go aggressive then I think I can do okay.

But jungling has eluded me for some time. I initially gravitated towards the more "assassin" types of junglers, like Kha'Zix and, to a lesser degree, Fiddlesticks. For whatever reason, I can't get them to work for me. I think a part of this is that I'm not familiar enough with the ganking routes and angles to effectively assault a lane and secure a kill. That's probably something that only comes with experience but, while I'm trying to gain the experience, I really don't want to suck for my team. I've had Kha'Zix games where I go 0 kills and that's just not acceptable.

Amumu plays similarly to Malphite, whom I'm actually pretty good with. They're both tanky, initiators with fairly straightforward builds. Malphite tends to be a little more Armor tanky while Amumu is a little more AP tanky but other than that, they're very similar. Amumu has really good jungle clear times mid game due to bandage toss and massive aoe damage. This lets him continue to farm his jungle well into the late game when other junglers are typically focused on team fights. He also clears waves very quickly making him great for cleaning up pushed lanes and getting massive late game gold infusions. I had a nearly full build by the 30 minute mark last night.

A couple things I learned about him.

Don't be afraid to try things with the bandage toss. You're going to get it on a relatively short cooldown by the time you hit 18 (8 seconds less whatever CDR you have). The bandage toss works like a slow deploy wall so throwing it slightly in front of people (even at close range) is probably a good idea. Anyone who walks into it will be hit (even if they aren't hit by the leading tip). I got a kill on Ezreal last night when I threw it blindly after losing vision on him.

Your Despari (W) can be activated mid bandage toss. Don't wait to land, you want to be doing the damage the instant you arrive.

The cooldown on your Tantrum (E) is long enough, even in team fights, that you should wait to melee a target before applying it. Your passive will reduce a target by 35 MR at 18 and your Abyssal Scepter by another 20. So most targets will be reduced to nearly 0 MR if they haven't built tanky. Because of the way MR works, the last reduction is far more important than the first reduction so getting Bandage Toss, Despair, Auto-attack, Curse, Tantrum is a big deal.

Your Curse of the Sad Mummy (ult) is not a stun but it sure feels like one. It stops movement and auto-attack for 2 seconds. Against AD or melee heavy teams that's huge. Positioning is critical. You want to be close enough to the ADC that they can't escape out. If you can land a bandage toss on the ADC or APC, you generally are going to keep them in place for 3 seconds (or at least within range). Remember also, it's not a channel. You can move around freely after you cast it. Take the opportunity to apply your passive debuff to everyone within easy range.

Maxing Tantrum first is a big deal. Tantrum scales up well (+25 damage per level and -1 second CD) without increasing mana cost. The fact that it's passive can very quickly make jungling danger a non-factor (while simultaneously making you tankier in team fights) is just icing.

Your build should be (in some order), Sunfire Cape (2500), Abyssal Scepter (2650), Rylai's (2900), Boots, Spirit of the Spectral Wraith (2400). The sixth item is going to be something like Runic Bulwark (for team tankiness) or Liandry's (for more damage against high health targets) but is unlikely to ever get built (making me a sad mummy). Generally, I'd prefer to rush the Sunfire Cape but if the laning phase looks like it's going to last longer, Rylai's could be a good investment for maximizing ganks. Late game, once you've purchased Spirit of the Spectral Wraith, resist the urge to recall after a low health team fight. Instead, go back and farm Wraith, Wolves, Golems, Wraith and note your health returning pleasantly.