Can Rocket Boots be found in Chests?
No, the Rocket Boots cannot be found in any chests, nor do they drop from anything including shadow orbs, any enemies or bosses.
They can only be acquired by purchasing them from the Goblin Tinkerer for 5 gold.
Rocket Boots are not dropped by any mob on the game or found in any chests, they are sold by the goblin tinkerer NPC who is usually found in the underground jungle after the goblin invasion has been defeated at least once.