Kog'Maw vs Yone

Start your trades with Caustic Spittle (Q): it reduces the target's armor and magic resist, and its ranks also give you permanent attack speed.

Activate Bio-Arcane Barrage (W) right before the teamfight: it extends your attack range, and your autos deal damage based on the target's max health.

When an enemy runs at you, cast Void Ooze (E) between you and them: the trail of ooze slows everyone who crosses it.

Save Living Artillery (R) for targets below 40% health, where it deals its max damage: each shot fired in quick succession costs more mana.

Get out of his line after two Mortal Steel (Q) hits: the next one makes him dash forward and knocks the enemies hit into the air.

During Soul Unbound (E), avoid taking hits: when he snaps back, part of all the damage he dealt you is repeated.

If you have ground-targeted CC, place it on the body he left behind: when Soul Unbound (E) ends, he has to return there.

Judge his threat by his crit items more than his level: Way of the Hunter (passive) raises his critical strike chance, so each crit item does more for him.

In teamfights, don't line up with your allies in front of him: Fate Sealed (R) hits every enemy in a line and knocks them into the air toward him.