101Leafy researched the games.
Gravios Spear

Lance crowned with the name Gravios. One false step and you may befall its venom.
| Class | Lance |
|---|---|
| Rarity | 5 |
| Attack | 345 |
| Poison | 250 |
| Defense | +5 |
| Slots | 0 |
| Price | 30,000z |
Upgrades
| Upgraded from | Basarios Venom Spear |
|---|---|
| Upgrades into | Gravios Venom Spear |
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 748.