After i defeat the goblin army and left the game

[5uperJ!mmY™]

Will the Goblin Tinkerer still be bound in the cavern layer when i reenter ?

[curiositas]

Yes.
The Goblin Army is registered as defeated in the world, so the Goblin will spawn at any time in the Caverns.
That is unless you didn't save the game in some sort of way.

[5uperJ!mmY™]

thanks, do u have any tips for finding cavern ?

Originally posted by Aero Cony:

Yes.
The Goblin Army is registered as defeated in the world, so the Goblin will spawn at any time in the Caverns.
That is unless you didn't save the game in some sort of way.

[curiositas]

Originally posted by Jimmy:

thanks, do u have any tips for finding cavern ?

https://terraria.gamepedia.com/Cavern

The Cavern is found on a certain depth, with the layer start depending on your world size, stated under the link I provided.
You can use a Depth Meter to determine when you are in the Caverns or still Underground.

[5uperJ!mmY™]

the goblin npc will only last for that world only ? stil looking for him in the cavern so hard to find ...

[curiositas]

Originally posted by Jimmy:

the goblin npc will only last for that world only ? stil looking for him in the cavern so hard to find ...

The tied Goblin NPC will only appear in the worlds where the Goblin Army has been defeated. And once you free the Goblin, he will respawn on daytime with the obvious conditions.

You can use a Hunter Potion to ease up finding the NPC as he will get highlighted.

[VagueCryptid]

The Tied Goblin should spawn in the world just like any monster, skeleton, or critter. He spawns deep, so utilizing the Dungeon or a Hellevator should help you find him.

Once you find him, and untie him, he will respawn just like normal NPCs, so you don't have to find him again. Just make sure he has a house.