Gnar is a form-swapping fighter-tank who excels teamfights, splitpush, and the lane. He has many diverse build paths and play styles. He should be on your list to pick up for an all around fun and super strong top laner!
Gnar takes some patience to learn, as his rage bar can feel difficult to control until you understand it. This is especially true in solo queue, where almost no one will play around your rage. Don't give up! With enough practice, you can master Gnar.
Pros / Cons
[*] Ranged mini form allows you to poke and trade effectively til you transform
[*] Mega form does insane damage and cc
[*] Gnar has very few bad matchups
[*] Difficult to master controlling transitions
[*] Requires team to play around current rage and status of abilities
[*] If behind by too far, can't impact map by creating pressure