Here's what I've gathered so far:
- There's a new token available called Brittle Candy
- Brittle Candy can be used to purchase a set of new Dark Harvest costume helmets: Paper, Replica, and Authentic Scarab Masks
- Brittle Candy is acquired from Grim Gourdings. One Gourding drops 1 or two Brittle Candies.
- Grim Scarabs sometimes spawn from graves, as Zombies tend to do. When a Grim Scarab is killed, a Grim Gourding spawns in its place.
- A number of Grim Scarabs are guaranteed to spawn in the final level of The Dark Harvest (daily prestige mission)
- The mission An Occurrence at Owlite Keep (rank 9-1) is highly recommended for farming these.
- There's a new material called Punkin Sprout (picture)
- These can be purchased from Maskwell with 20 of any kind of Candy token.
- Punkin Sprouts can be used to craft a Maskeraith Pod (Punkin).
Further reading:
http://wiki.spiralknights.com/Dark_Harvest_Festival
http://forums.spiralknights.com/en/node/66600
https://www.google.se/search?q=site:forums.spiralknights.com+candy+farming
Grim Scarabs are their name. They also spawn in graveyards from what we found (I think 1/100)