Monster Egg
Monster Eggs are a variety of stone block that spawns Silverfish when broken. Monster Eggs have identical looks to either Smooth Stone, Cobblestone, or Stone Bricks, and are naturally found in strongholds and rarely in Extreme Hills biomes, hiding among the true blocks. When breaking it with a pickaxe it takes noticeably longer to mine than regular stone, cobblestone, or stone brick, making it relatively easy to distinguish from the regular blocks, if one is careful enough. The block can also be destroyed by hand fairly quickly, unlike regular stone blocks. Mining a Monster Egg with a Silk Touch enchantment does not give the player a Monster Egg block, but the type of block that the Monster Egg is disguised as. As such, Monster Eggs cannot be obtained as an item outside of Creative mode.
If the player attacks a Silverfish directly, nearby Monster Eggs will break, spawning other aggressive Silverfish, which can swarm any passing victim if unprepared. When a Silverfish is not pursuing the player, the Silverfish will go to the nearest stone, cobblestone, or stone brick and go inside it, converting the block into another Monster Egg.
