101Leafy researched the games.
Crabby Castanet

Holy item used by ancient people during festivals, turned weapon through valor.
Blowing air into it makes the claws strike the shell, producing a sound like a percussion instrument. It is said to have been used in rituals by an ancient people who no longer exist. That people reportedly stepped and danced to its quick, rapid-fire beat.
Our translation of 復刻 ハンター大全 (KADOKAWA / Enterbrain, 2014), page 159.
| Class | Hunting Horn |
|---|---|
| Rarity | 9 |
| Attack | 1300 |
| Defense | +28 |
| Slots | 0 |
| Notes | Purple, Green, Red |
| Table price | 90,000z |
Songs
| Notes | Song | Effect |
|---|---|---|
| Purple, Purple | Movement Speed Up | Faster movement with weapon drawn for 3 min *2 |
| Purple, Red, Red | Attack Up [Hi] | Attack +15% for 1 min 30 s |
| Red, Green, Red | Defense Up [Hi] | Defense +20% for 1 min 30 s |
| Purple, Green | Health Rec [Lo] | Restores 20 health (33% chance) or 10 (67%) |
| Green, Red, Green, Purple | Recover Spd Up [Hi] | Red health recovers 3× as fast for 2 min |
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 166.
Upgrades
| Upgraded from | Shell Castanet |
|---|---|
| Upgrades into | Klick-Klack |
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 740.