Also Anim your obviously not playing at a very high ELO if you think Kog'Maw is useless. His superior range means he is ridiculously powerful in the laning phase and also he is one of the best Chasers in the game. Damage output also gets ridiculous when you go pure AP which is what all the good Kogs are doing these days.
Where are you experiencing these amazing kog'maws then? Some stats say you're around the lvl 20 mark
![Frown :( :(](/styles/default/xenforo/vbSmilies/Normal/frown.gif)
Either way, just as an aside, kogmaw doesnt really chase, has a skill shot slow that is avoidable (with ease if youre at any distance) and no in built speed to speak of unless he dies. Casters that bring more to a team fight (a number of which are better laners also):
Amumu (not typical caster but as you know, magic based and can do a lot of aoe, snare, stun)
Anivia (Mid/Laner, Slow, stun, massive damage and spike damage)
Annie (Mid/Laner, Aoe stun, aoe massive damage, single target finisher, extra target in ulti)
Fiddle (Mass silence, aoe damage, fear)
Heimer (Mid/Laner, Mass blind, aoe damage, stun, slow)
Morgana (Mid/Laner, Initiator shield, aoe slow + stun, aoe damage)
there are others that simply do more damage in the team fights or have some unique utility but didnt bother including them as its not what the focus is here.