Perfect for hunting.
The item id for Easter Harpoon in unturned is 6678. You can use this ID with the commands below to spawn the item, give it to a player or buy it on a modded economy server.
Size_X: 2
Size_Y: 1
Size_Z: 0.33
Amount: 1
Calibers: 1
Caliber_0: 6678
Tracer: 48
Stuck: 10
Blueprints: 2
Blueprint_0_Type: Supply
Blueprint_0_Supplies: 1
Blueprint_0_Supply_0_ID: 67
Blueprint_0_Supply_0_Amount: 4
Blueprint_0_Tool: 76
Blueprint_0_Level: 1
Blueprint_0_Skill: Craft
Blueprint_0_Build: 27
Blueprint_0_Product: 6678
Blueprint_0_Map: Easter
Blueprint_1_Type: Repair
Blueprint_1_Supplies: 1
Blueprint_1_Supply_0_ID: 67
Blueprint_1_Supply_0_Amount: 2
Blueprint_1_Build: 27