(Goblin Thicket isn't a spell.)

At the beginning of your end step, if you didn't cast any spells this turn, Goblin Thicket deals 1 damage to you.

Goblin Thicket is indestructible. (Destroy effects and lethal damage don't destroy it.)

: Add  or to your mana pool.

Put Goblin Thicket on top of your library: Add  to your mana pool.