Spikey trap.
The item id for Snare in unturned is 1113. 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.
Useable: Barricade
Build: Spike
Size_X: 2
Size_Y: 1
Size_Z: 0.275
Health: 1
Range: 4
Radius: 0.05
Offset: 0.075
Player_Damage: 10
Zombie_Damage: 175
Animal_Damage: 175
Explosion: 36
Blueprints: 1
Blueprint_0_Type: Barricade
Blueprint_0_Supplies: 2
Blueprint_0_Supply_0_ID: 67
Blueprint_0_Supply_0_Amount: 5
Blueprint_0_Supply_1_ID: 65
Blueprint_0_Supply_1_Amount: 2
Blueprint_0_Build: 27
Has_Clip_Prefab: false