From RoR Wiki
Marsh Choppa is a Tome of Knowledge Achievements unlock for the Exploration section.
Unlock for Order & Destruction
- Marsh Choppa
Interact with 'Marsh Axe', an axe in a helm, in Marshes of Madness at 32.8k 5.1k, inside 'Marshfang Spider Cave' (entrance at 28k 7k).
- XP: 150