101Leafy researched the games.
Cephalos

Wyverns found only in the desert. They resemble a Plesioth, but live and "swim" in sand rather than water. They seldom appear above land, but when their hearing is disturbed...
Monster List No. 22
Carving
Number of carvings: 1 (BradyGames, Monster Hunter Official Strategy Guide, 2004, p. 86). The guide (p. 78) splits the carves by Quest Level: early quests are levels 1 to 3, latter quests 4 to 6.
Early quests
| Item | Chance |
|---|---|
| Piscine Fang | 15% |
| Piscine Liver | 30% |
| Piscine Liver | 30% |
| Cephalos Scale | 15% |
| Cephalos Scale | 8% |
| Cephalos Fin | 2% |
Latter quests
| Item | Chance |
|---|---|
| Cephalos Fin | 15% |
| Piscine Liver | 30% |
| Piscine Liver | 30% |
| Cephalos Scale | 15% |
| Cephalos Scale | 8% |
| Piscine Fang | 2% |
Quests
No quest names it in its title or goal.