Diamond Horn is a hat item which is June 2017's Item Of The Month. The items adds mod called "Energized Horn" which adds ability to build 1 block further.
The Diamond Horn is actually 3 items that can be changed by un-wearing and wearing the horns. Doing so will change the horn into another one.
1st form (Diamond Horn) : Retextured version of Unicorn Horn with Focused Eyes like punch effect.
Purchase the Diamond Horn for 100,000 in the Growtopia Store.
"June 2017: Diamond Horn! This amazing horn transforms each time you unequip it. Try all 3 flavors! It also boosts your build range. This item can only be purchased this month! It will never return, and cannot be obtained any other way! It is tradeable, though. There is a link in the /news if you'd like to see a short clip of the item in action before purchasing."
Every purchase will give 1 item.
Dupe Exploit
On the 1st of June 2017, a duplication exploit was found for the Diamond Horn involving the Phone Booth which resulted in 1300 players being banned. 600 of those were perma-banned. Some exploiters had their Diamond Horns removed and were unbanned.