Just letting you know . . .

My build is weird. But I start with Ancient Coin for the passive gold. Aggressive lane. Infinite poke with Q. Build Sightstone first as a support basic, imo. Then build as you would a normal Gnar. You can use the poke and a couple of autos on full health minions to balance Gnar's passive between 90-100. And then if you get ganked or wants to engage, turn into Mega Gnar, ult and make plays. It's beautiful, really.