The Lava Slime is a variant of Slime only found in the Underworld. The Lava Slime can jump higher and further than normal slimes, in addition to having immunity to Lava, which they float upon similarly to other slimes floating on Water. The Lava Slime can inflict the On Fire! debuff.
Terraria - New UNDERWORLD MONSTERS
Notes
Lava Slimes appear to be on fire, giving off light that can be detected on the side of the screen, to give warning of the approaching danger.
Despite their resistance from the On Fire! debuff, the Imp Staff's summoned Imp is still very effective against it.
They don't drop Gel.
Lava Slimes can sometimes fit through 1 block gaps.
The lava slime's threat level is comparable to that of the Jungle Slime, even though the jungle slime does have higher stats.
Unlike other slimes, the Lava Slime does not drop Gel on death.
However, a Lava Slime creates now one Lava Block on death since 1.3.0.1 (Expert Only)
When building a bridge to deal with the Wall of Flesh in Expert Mode, it is advisable to leave one-block breaks in the bridge periodically. This is to allow Lava from defeated Lava Slimes to drain instead of pool up on the surface of the bridge.
These should be dealt with quickly, as Lava Slimes are much faster then your average blue or green slime.
