Lava Boulder

It behaves like an ordinary boulder trap right up until it breaks. Then it dumps lava into whatever open space is next to it, which turns a survivable hit into a flooded tunnel and a burning character. It only appears near lava that already exists, so treat every boulder you meet down there as this one.

It glows while rolling and flares brighter each time it bounces off terrain, so even in a dark cave you get a warning before it arrives. If one is coming down a slope at you, do not stand and shoot. Step aside and let it pass, or break it from far enough away that the spill lands somewhere you were not planning to walk.