Some bugs I found in practice tool

Boomerang Throw throws the projectile from the point where Gnar started his cast time, rather than where he ends it. For example, if he uses Flash during Q then he should throw his Q from the position he Flashed to. Instead, he throws it from the point before the Flash. This also affects when he uses Q during his E.

Gnar's Q return indicator doesn't draw over terrain.

Gnar's emotes don't always play audio if they are started while another emote is playing. It seems to not play if the audio of the initial emote is playing. In Gnar's dance, the rattle noise plays, but his voice does not. This looks especially weird since his mouth movements do not line up with his voice.

Normally, Flash cancels movement input if you use it in the opposite direction that you are moving in. However, if you use Flash during Gnar's Q or E, you will always continue your previous movement input. This can result in you Flashing to get away only to move right back towards the enemy. Furthermore, using Flash during Gnar's E does not allow him to bounce off of a target if he lands on them and it does not grant him the attack speed buff unless he Flashes after bouncing off of a target. The attack speed buff is granted when he lands, but it is granted for bouncing on an enemy champion and then refreshes after the second jump. These also happen with Blast Cones.

On the topic of Flash stopping movement when going in a different direction, it will pick the movement command back up if you Flash again in the initial direction of the movement command. So you input a movement command, then Flash in the opposite direction to cancel said movement command. You Flash again in the initial direction of the movement command and the movement command completes. You can also finish moving to the spot, Flash away, and then Flash again and you will go back to that same spot. Dashes do not count as movement commands, so you can dash away, then Flash towards your last right click spot and you will walk back to that point. This specific part can affect non-Practice Tool games.

Gnar generates Rage whenever he attacks a plant. These are supposed to be considered out of combat interactions, so they should not give rage.

Plants that have been seen before but are currently in fog of war do not have shadows. The shadows reappear as soon as they are in vision.

Statikk Shiv (and I assume RFC/Kircheis Shard) do not gain extra stacks from attacking when combined with Guinsoo's Rageblade.

Attack move click is a bit bugged. You cannot use attack move on anything but minions, turrets, or champions, except by directly clicking on the target. Using target champions only does not stop attack move click from targeting minions or towers like it should when used in conjunction with attack move. However, it does stop you from at all targeting other things like plants and jungle monsters, even when you directly click on them. You also automatically target champions that are outside of your basic attack range, even if you click in the opposite direction. It should only move towards the enemy to get into auto range if you click towards the enemy.