Leeches cause significant damage in high numbers, and should be dealt with immediately after spawning. They drop hearts which can be very useful in healing the player during the boss fight. They also drop Mana Stars if killed while the player doesn't have a full Mana Bar.
- Leeches do not cause the same "digging" noise characteristic of other burrowing monsters.
- If you kill the Wall of Flesh, any leeches you haven't killed yet will still attack you.
- Added to the game.