Spike Grenade

A new addition for Halo 3, the Spike Grenade works a bit differently than frag or plasma grenades.

Like a plasma grenade, it will stick to targets. Unlike a plasma grenade, it will also stick to walls, floors, and ceilings. Also unlike a plasma grenade or a frag grenade, it unleashes damage in a conical pattern away from the surface to which it sticks.

Full lowdown on this weapon can be had from Bungie.net:

Brute Grenade Top Story

UPDATE: In the Halo 3 Public Beta, the number of grenades per type that can be carried simultaneously is in fact two.