There are a handful of Blocks in Minecraft that are not as harmless as they seem. These Blocks are usually an indicator of a nearby Mob. Read on to learn more about these Mob Blocks and what you may need to watch out for nearby.

List of All Mob Blocks

Spawners

List of Blocks
Spawner

The most recognizable of the Mob Blocks is likely the Spawner. In the Overworld it can be found in dungeons, abandoned mineshafts or by End Portals. In the Nether, they can be found in Nether Fortresses.

The spawner appears like a small cage that, in the right conditions, periodically spawns the mob that can be seen within it. Be prepared for combat when approaching these Mob Blocks.

Infested Blocks

List of Blocks
Infested Stone	Infested Cobblestone	Infested Stone Bricks	Infested Mossy Stone Bricks
Infested Cracked Stone Bricks	Infested Chiseled Stone Bricks

Although appearing almost exactly like their Stone Block counterparts, Infested Blocks are home to the annoying Silverfish. When these blocks are mined, they will spawn a Silverfish which will then target the player. Be careful not to be overwhelmed by the little buggers.

List of All Stone Blocks and Variants

Sculk Blocks

List of Blocks
Sculk Catalyst	Sculk	Sculk Vein	Sculk Shrieker

The Sculk Catalyst is responsible for the creation of other Sculk Blocks. When mobs that drop Experience are killed nearby, a Sculk Catalyst will convert viable blocks into Sculk Blocks. Most of these Sculk Blocks can be found in the Deep Dark Biome.

How to Find the Deep Dark: Mobs, Structures, and Tips

Blocks Related to Bees

List of Blocks
Bee Nest	Honeycomb Block

Bee Nests house the neutral mob, Bees. These Bee Nests are necessary in producing Honey and Honeycomb. Honeycomb gathered can then be crafted into the decorative Honeycomb Block.

Blocks Related to Frogs

List of Blocks
Frogspawn

Frospawns are blocks that are produced when two Frogs breed near water. After one of the frogs lays the Frogspawn, it will take a few minutes for a new cluster of Tadpoles to hatch.

Minecraft Related Guides

List of All Blocks

List of Block Categories

All Block Categories
Aquatic	Banner	Concrete	Creative
Dirt	End	Glass	Head
Light	Mineral	Mobs	Nether
Plant	Redstone	Stone	Terracotta
Utility	Wood	Wool	-