KOG MAW and URGOT
I believe that these two champs have not been given the attention they deserve by the summoners, not many play these champs. I believe that modifying these champs to make them more appealing to the summoner would be quite nice.
Most people ignore urgot because they believe that his ultimate isnt that worthy, i believe this to a certain extent. So i propose this, why not make his ult so that when he uses it on an enemy, lets say a teemo in this case the ultimate not only switches the positions and adds more MR and armor, but also switches debuffs. So any poisons on urgot would be transferred to teemo. This effect could ignore stuns ( i dont think its possible to use this stun during stuns anyway). So effects like lindary's, teemo's poisons, red buff could be switched when the ultimate is used for the duration of the debuff remaining. Not all champions use these debuffs so urgot will not get OP. And considering hte short range and the long CD of the ult it should be pretty balanced.
Kog maw is seriously under rated too, though he is pretty balanced i believe that his slow should consume a bit less mana as early game it is quite demanding. (from 2-7 mins before a mana regen item is bought) and it is usually your bread and butter spell till you get your ultimate, after which it is a combination of those two which is used for farming and harassing. So i believe that the attack should consume a bit less mana.
Besides the abilities, their skins could be reworked a bit also and the ability's looks could be made to be a little better.