Lavaflies will spawn occasionally in the Underworld at night. They can be caught with a 防熔岩虫网 or Golden Bug Net to be carried around and released later, or put in a bottle to be used as furniture and a light source.
- Like Fireflies, Lavaflies are difficult to see in the Underworld at high resolutions, appearing as a blinking speck on the screen.
- 熔岩蝇的 怪物图鉴条目：“萤火虫的变种，适应了世界地狱核心的紧张环境。长得像火花的余烬。”
- 电脑版 188.8.131.52：Introduced.