The Knight Helmet is a sponsored item that is worn on the head. It was sponsored for 3,000 World locks.
In game description:
"This helmet was forged by the awesome art god Hamumu. Sponsored by Knightmare."
Rarity: 57
To grow, splice a Grimstone Seed with Steel Girder Seed.
This item never drops any seeds.
Additional Info
The Knight Helmet was sponsored at a cost of 3,000 World Locks. This item was released on the 8th of August, 2014 during the Player Appreciation Week.