How to make ZZ'Rot less annoying
First off, increase the cooldown to five minutes, but reduce the cooldown by half whenever it's killed.
Second, take away the minion's 'meatshielding' ability. There's no reason they should block skillshots if they're not giving me any gold or exp for killing them.
Third, give the portal a set amount of health so it's easier for non AD champs to kill.
And finally, increase the gold when destroying it to 50.