101Leafy researched the games.
Bone Horn

An enormous Hunting Horn. Its tone inspires hunters to unlock the power within.
| Class | Hunting Horn |
|---|---|
| Rarity | 2 |
| Attack | 572 |
| Defense | +5 |
| Slots | 1 |
| Price | 1,575z |
Upgrades
| Upgraded from | Cyclo-Hammer |
|---|---|
| Upgrades into | Bone Horn+, Blessed Ocarina |
Upgrade tree from モンスターハンターポータブル 2nd G 公式ガイドブック (Enterbrain, 2008), page 730.
Materials
Hard Ticket ×1, Brute Bone ×1