Ok, so anyone who had played the game for awhile and pays attention to HotS Logs knows that Murky is basically a non-hero right now. He is objectively the worst hero in the game and his 38.7% win rate attests to that fact.

I can't begin to tackle the redesign needed for him alone but I think have an idea for one change that would begin to help his pitiful plight.

Change to Pufferfish: After throwing the fish, allow Murky to activate the ability again after a tiny delay to blow up the fish early. Blowing up the fish early does reduced damage based on how early it is detonated, but with a bonus for damage against heroes.

So for sake of argument, let's say the fish does 50% damage when blown up immediately but has a 40% percent damage bonus against enemy heroes, so 40% of 50% means Pufferfish would do 70% of total damage against heroes when blown up immediately. Those numbers might be too high, but the idea is for Pufferfish to be used on its full fuse mainly against creep waves for laning, but it can still be used as a skill shot against enemy heroes, though it's damage will be severely reduced against creeps when used to harass.

This change would make Murky more of a presence in lanes and have more options to do damage other than sliming and the odd rarely-hit pufferfish. It would also make the Wrath of Cod ability actually useful and allow Murky to be more effective in team fights.

To keep Compressed Air balanced, so that you aren't immediately detonating unavoidably gigantic pufferfish, the 50% range increase could grow over the duration of the pufferfish, to reach max range as the fish blows up.