Why does this aircraft land nose first?
That's pretty much how landings turn out on Super Guppy. The aim is to make a three point landing (main and nose wheels touch down simultaneously), but the Super Guppy is a tricky plane to land. Earlier versions were tricky on takeoff too: during takeoff roll their main gear tended to lift off before the nose wheel, this, ofcourse is far from optimal...

This article will give you a nice briefing on this beautifully weird plane (see page three for stuff about landing).

The ones still flying are fitted with Boeing 707 nose gear, which is shorter, sturdier and placed further behing than the original one. Despite this modification, the aerodynamics of the plane are such that it just wants to plant the nose wheel down first. Searching "Super Guppy landing" on Youtube will yield allmost only nosewheel landings.