Example end build
Sup boiz, it's your man Arcesta here to bring you the most pogchamp, kappa123, xd Jesus xd guide for Hecarim out there. Hecarim is probably the most freel0 jungler out there if you aren't a boosted monkey and dont smash your face on the keyboard like most NA players do while playing League of Legends. By following my guide you will successfully 1v9 and carry your elo boosted bonobo team straight out of early game into a 20 minute double enemy nexus explosion.
Greater Mark of Attack Damage
Greater Seal of Armor
Greater Glyph of Magic Resist
Greater Glyph of Scaling Cooldown Reduction
Greater Quintessence of Movement Speed
Greater Quintessence of Attack Damage
On Hecarim you either go tank and hope your team knows how to play around that or you can just assume they will feed like they are attempting to end world hunger, and follow my build path.
We start Hunter's Machete Refillable Potion and Warding Totem like most junglers. Our first back consists of Boots of Speed and either a Stalker's Blade or Aether Wisp depending on if you want more reliable clears over the next few minutes or more damage on some of your abilities... you should usually just go stalker's.
We finish mid game with Stalker's Blade - Runic Echoes Trinity Force and Boots of Swiftness then assess how the game is going. Your next item should either be a Maw of Malmortius if mid or top fed their ap lane into obesity, a Dead Man's Plate if bot/top/mid fed their ad lane into obesity, or if none of the above and you were a successful jungler and got ridiculously fed, pick up a Youmuu's Ghostblade or Hextech Gunblade to keep yourself snowballed.
Finish up the game with any combination of the items i have recommended to suit the game you are in.
Skill SequenceRampage is the best skill to max since it is your main source of constant damage. Devastating Charge is next since it is a hard cc, makes your ganks more effective, and procs your Courage of the Colossus just like Onslaught of Shadows which you should be putting points into when you can (levels 6,11,16). Spirit of Dread is maxed last since it is probably the least useful of your skills to put points into early.
Creeping / Jungling
If you start blue buff take wolves next then red and look to gank, if you start red buff take wolves then blue then gank. Ganking with your double buffs is the best way to gank as it gives you more damage and cdr and afterwards you will regenerate any hp/mana lost. Try not to die, your mid laner will not forgive you if you give a syndra/zed double buffs at 4 minutes.
Hecarim should never have trouble clearing once he gets his Stalker's Blade, Spirit of Dread heals you as well as your smite, and since you are in the jungle your jungling item regens your mana.
If you get counterjungled just counterjungle back once the enemy shows themselves in a lane, your Devastating Charge and Ghost make it near impossible for most junglers to catch you.
Try to countergank if possible, Hecarim has two powerful disengage tools in the form of his E and ultimate, which should help you stop the gank or come out on top with a kill.
This is league of legends, odds are your team is four wood 6 chimpanzees who paid to get rushed to level 30. Don't expect a carry, that's going to be on you. Early game you can try to gank with double buffs, that is your most powerful time early until you get Stalker's Blade - Runic Echoes and Onslaught of Shadows. Later on try to secure dragons, avoid rift herald unless you find a time with 2-3 enemies down, and focus their squishies. This build is for damage and until late game Courage of the Colossus only gets you so far, so try to wait until your bonobo team is there to 1v5 and hope they get a skillshot or something off, depending if their keyboard is plugged in or not.