Monsters are what turn foot traffic into money in Build Your Backrooms. Each one you place catches visitors and NPCs that wander into your maze, and every catch pays out cash based on that monster’s multiplier. You start with the Wanderer, the weakest option, and unlock stronger catchers as you rebirth.
Quick answer: There are 11 monsters. Two are available by default, and the rest unlock across Rebirth 1 through Rebirth 6. The Grasper is the strongest at a 7x cash multiplier, and it costs 75,000,000 Cash after reaching Rebirth 6.
All monsters, prices, and cash multipliers
Every monster is bought from the Monster Shop with Cash. Higher multipliers mean bigger payouts per catch, so the goal is always to move up the list as your rebirth level allows.
| Monster | Cost (Cash) | Multiplier | Unlock |
|---|---|---|---|
| Wanderer | 500 | 1x | Default |
| Smiler | 1,800 | 1.2x | Default |
| Hound | 9,000 | 1.55x | Rebirth 1 |
| Crawler | 25,000 | 1.85x | Rebirth 1 |
| Siren Lamp | 80,000 | 2.25x | Rebirth 2 |
| Water Dweller | 220,000 | 2.65x | Rebirth 2 |
| Hotel Keeper | 650,000 | 3.1x | Rebirth 3 |
| Mimic | 1,700,000 | 3.7x | Rebirth 4 |
| Glitch Entity | 4,500,000 | 4.5x | Rebirth 5 |
| Red Watcher | 12,000,000 | 5.6x | Rebirth 6 |
| Grasper | 75,000,000 | 7x | Rebirth 6 |
How monsters unlock through rebirths
Only the Wanderer and Smiler are buyable when you start. Everything past the Smiler is gated behind rebirth levels. To perform a rebirth, you need to place a set number of buildings, unlock the required number of plots, and bank enough Cash for the reset cost. Each rebirth then opens new monsters in the shop.
- Rebirth 1: Hound and Crawler.
- Rebirth 2: Siren Lamp and Water Dweller.
- Rebirth 3: Hotel Keeper.
- Rebirth 4: Mimic.
- Rebirth 5: Glitch Entity.
- Rebirth 6: Red Watcher and Grasper.
The Cash requirements climb sharply at the top. Rebirth 5 and Rebirth 6 push the reset cost into the millions, so plan your building purchases carefully. Buying large numbers of the cheapest available room, such as Yellow Crossroads, is the most efficient way to hit the building count without draining your bank.
Best monster to aim for
The Grasper is the strongest monster in the game with a 7x cash multiplier. It becomes available at Rebirth 6 alongside the Red Watcher, and it costs 75,000,000 Cash. Before you can afford it, the Red Watcher at 5.6x serves as the top earner while you save up.
A monster’s multiplier is only half the payout. Where you place it matters just as much. Putting your strongest catcher in a high-multiplier room near the visitor spawn secures the biggest payouts, since visitors get caught immediately instead of wandering into lower-value sections of your maze.
Buying and confirming a monster
If a monster is missing from the shop, you have not reached the rebirth level that unlocks it yet. Check the unlock column above, rebirth to the required level, and it will appear for purchase. You can jump straight into the game from its Roblox page if you want to check the shop yourself.
Work through the list in order as your Cash and rebirths allow. Swapping out weaker monsters for higher multipliers, then pairing them with your best rooms, is the most reliable way to scale earnings from the starting Wanderer all the way up to the Grasper.
