EastScape Wikibuilt from the game itself

Frost seeds

Where to find it: Cloudreach (Cumulus Ram; Brainstorm; Sea-Goat of the Upper Air), The Thunderhead (Thunder Goose; Thunderwolf), The Deep Wild (Grim Lich; Yard Gator), The Golden Sands (Sand Cobra; Tomb Jackal), The Trailer Park (Yard Gator), Glasswater Wastes (Brinepicker).

“Plant them on your island. They grow the flower that element's ink is brewed from.”

Dropped by

MonsterLevelHow manyChance a killRoll
Brinepicker1101–210%One of the table
Grim Lich6612.5%Own roll
Cumulus Ram421–20.8%Own roll
Thunder Goose551–20.8%Own roll
Brainstorm401–20.8%Own roll
Sea-Goat of the Upper Air461–20.8%Own roll
Thunderwolf581–20.8%Own roll
Sand Cobra481–20.8%Own roll
Tomb Jackal471–20.8%Own roll
Yard Gator921–20.8%Own roll
Restless Ghost (deeper)551–20.8%Own roll
Bone Golem (deeper)581–20.8%Own roll
The Auditor421–20.8%Own roll

Grows

Plant it on your island's plots (Harvesting 35): ready in about 120 minutes, logged in or not.