101Leafy researched the games.
Giaprey Balloon+

Based on a Giaprey head. Inflating its windpipe mimics a Giaprey's call.
| Class | Hunting Horn |
|---|---|
| Rarity | 3 |
| Attack | 520 |
| Ice | 150 |
| Slots | 0 |
| Price | 1,935z |
Upgrades
| Upgraded from | Giaprey Balloon |
|---|---|
| Upgrades into | Giadrome Balloon, Velociprey 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 736.