You take fervor, because it helps you keep up with the damage, that the other laner has, it can also get you a few kills. You can also take Grasp, but after the nerfs I think it's not even worth, not even for new players.

So Gnar, Gnar is a very hard-to-master champion, so I decided to make this guide for new players who are just starting out playing Gnar. Gnar is an off-tank ADC or an ADC off-tank, goes the same way.

Start with dorans blade and pots when you are against melee champs that can't reach you and you can harrass easelly like Darius or Maokai or Malphite. Take dorans sheald against ranged and lane winning champs that can jump on you easelly, like Illaoi or Quinn or Jayce

Laning as Gnar is very simple: levels 1-2 Farm and harrass when you can, when you are level 3 you can be a little more brave because you have a reliable escape now. At lever 3 when you are about to turn Mega don't be afraid to jump or even flash on your opponent (if he has no escapes of course), and do your e,aa,w,aa,q,aa(if you can get the last auto attack) combo, if you harrassed well enough the opponent should get killed. Make sure to watch out against enemy power-spikes, and winning lane is not a neccessity as many people think. Because you are a tank you don't need to be fed when it gets to grouping stage. Make sure to farm well and you should have around 100 farm by 10 min. if so you should already have your Frozen Mallet or be very close to it. When it's time to group you should already have your Frozzen Mallet and Black Cleaver, as the game goes along pick up ressistenses that you need the most.

On Gnar you always build frozen mallet first, its just the better option, I played around 300 games with Gnar now and as many times that I was ahead rushing Black Cleaver wasnt a very good choice, because I just couldn't stay on them. Some might say, but Cleavers Phage passive should give you movement speed right? Well, yes, but did you think about how little mobility does Gnar have and how long of a cooldown is he's e, its just not as optimal. You go black cleaver because it gives you enough health to you so that you won't be dying as Mega Gnar when you jump in at teamfights, plus it's very easy to stack as Mini Gnar with ur w. Next we go tanky items, because we already have enough damage from BC and Frozen mallet, and going tanky works the best because if you jump in as Mega Gnar with almost no Health and resistance items your going to get cc'd and killed emidietlly, so going tank is the most optimal option

Gnar has a very specific role when teamfighting. Before the teamfight he must have AT LEAST 60 RAGE. It's just needed if you want to have that juicy 3-5 man ultimate, and to survive. Before the teamfight starts i suggest you poke the other champions around to stack your rage and w, when you have enough rage, and your about to turn mega, u ping your team that your going in, MAKE SURE YOU INITIATE, SUPPORTS LIKE BLITZ AND THRESH DON'T INITIATE THEY JUST PICK OFF 1-2 PEOPLE. Your initaition goes something like this: When your about to turn mega, you e from a minnion, ally, jungle monster, enemy champion, etc. flash even, to the enemy team (the best moment is when they're clumped up). When you are in the middle of the enemy team, ult. Make sure to not ult into your ADC, or that may cause you to lose the teamfight, the best ult is usually into a wall or a support who can mass cc everyone. if your ult goes successful, do you r w,q combo on the enemy carry. MAKE SURE THAT U DON'T DPS THE SUPPORT OR THE TANK, YOUR PRIORITY IS THE ENEMY CARRYS. Be sure that your team is following you, COMMUNICATION IS KEY. One last thing make sure to not waste and force you're ultimate, as it is very precious and you need to save it for when the moment is right. Also be carefull before the teamfight to not get picked-off by a blitz, Thresh or something simmilar, you have a lot of cc on your team you are a very important role in teamfights!!!