101Leafy researched the games.
Bone Club

An unidentifiable, club-like bone useful only for training purposes.
| Class | Hammer |
|---|---|
| Rarity | 1 |
| Attack | 364 |
| Slots | 0 |
| Price | 400z |
Upgrades
| Upgrades into | Large Bone Club, Cyclo-Hammer, Bull Hammer, Giaprey Balloon |
|---|
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 722.
Materials
Mystery Bone ×3