Flamewalker

Flamewalkers are hostile melee mobs that spawn in the Nether.

Spawning
Flamewalkers will spawn naturally in the Nether at a light level of 7 or lower.

Behavior
Flamewalkers are melee attackers and will pursue players within 16 blocks. If the  gamerule is   and the Flamewalker is actively pursuing a player/mob or gets attacked, it will leave a trail of fire as it walks.

Immunities
Flamewalkers have the attribute of Fire Immunity and are completely immune to fire and lava damage.

History
烈焰步行者