101Leafy researched the games.
Graviton Hammer

Uses poison Basarios Shell. Occasionally poisons its monster foes.
| Class | Hammer |
|---|---|
| Rarity | 5 |
| Attack | 780 |
| Poison | 180 |
| Defense | +14 |
| Slots | 2 |
| Price | 4,900z |
Upgrades
| Upgraded from | Shell Hammer |
|---|---|
| Upgrades into | Crater Maker, Torment Hammer |
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.