IN THAT ORDER!
I hate getting Kog's on my team that do not use this build. Being able to fire 20 nukes with 40% CDR creates so much chaos for the enemy team. #1 champ damage guaranteed! No boots because you can stay a mile away from the fight when you get rank 2 ultimate, unless you are safe to go in. Did 60k+ champ damage in a 4v5 with the closes damage being 21k.
Ironclad Dragon3 votes
: "Opinionate! Exterminate!"
Worgslarg1 votes
Even more fun.
Ironclad Dragon1 votesThis isn't even a glass cannon.
Space Bum1 votesYou will run out of mana so fast with that. Disgusting!
Hyrum Graff1 votes
on 
in this order:
-> 
-> -> -> -> -> ->
Zarkkast1 votesThat build is awful, sorry.
A AP Kog'maw without Rylai and boots is not living up to his full potential.
This is what your AP Kog should look like: 
/ 
You should only ever get Morello if healing is becoming a problem, for example if the enemy team has a Sona and a Nami. You can consider getting Liandry instead of Void Staff if the enemy team is not building tank.
Space Bum1 votesThe Moselle is for CDR and mana regen. The grievous wounds is just a plus. Your build will not have as much damage potential because you buy unnecessary boots and dump a lot of gold on pointless health. So your build has less damage, CDR and mana regen.
Space Bum1 votesMorello
Zarkkast1 votesWith masteries and an elixir you have 35% CDR, if you buy Morello you go 55% which is just wasted itemization. With boots and a Rylai you can snipe anyone from the enemy team before any team fight even begins, it's impossible to escape your ultimate. You don't need more mana regen when you have Seraph's and Athene.
Space Bum1 votesI don't elixir on aram until full build and since you are paying 700 more for rylize maybe you shouldn't either. You can never have enough mana regen on Kog.