If Graves gets a shotgun for his Innate-

-why not let Koggy have a machine gun for his Innate?

Both have downsides. Lower than average ADC range. Graves with his reloads and Koggy with his inability to kite without losing significant damage. Can you imagine how much more awkward Graves' shotgun would be if it were just a buff with a cooldown? That's the boat Koggy is in right now.

Change his Innate to-

Bio-Arcane Barrage: Kog'Maw doubles his attack speed and attack speed cap, however his basic attacks deal 50% damage to champions and structures. Additionally, he deals bonus magic damage OnHit equal to (base percentage plus bonus AD ratio plus AP ratio) percent of the target's max HP.

Then remake his W so it's something a bit more interesting than just a range increase steroid. If Riot really wanted to get interesting, they could turn it into a toggle (Koggle-Toggle?) that physically roots him until you shut it off. Because Riot wants him to be the turret champion, right?