These are the basic build for Murky.
This is your murky's teamfight build. It is particulary good against melee AA hereos which include most tanks.
This is Murky's gank build. The purpose here is to lay down a slime/pufferfish/octograb combo and survive long enough to secure a kill.
This is Murky's dedicated push build. The idea here is to push a lane and the bubble away to a different lane when the enemy shows up. You can use March on building or join a team fight if it is up. Because of your escape and surviveability your Livin the Dream bonus will be up most of the time.