How do you beat a nunu-kog lane? You lose if you have even farm, and its hard to harass them without taking more damage.
The Kog'Maw-Nunu bot lane can be very devastating. Kog'Maw has some insane range due to his abilities and a slow. Nunu can give Kog'Maw increased movement speed and attack speed and also has two slows (one of which is AoE)
The key to countering this lane is to counter Kog'maw. However, there really is no strong counter against him. Some champions that do well against Kog'maw are:
One very important thing to remember: Do Not Feed The Kog'Maw! If Kog'Maw can get some early kills he WILL snowball and destroy your team.
Some information taken from a very useful guide by Crs Cop: