Fire beetle

A fire beetle is a type of beetle found on MM 9.

Glands

The glands are worth d10 gp each, since these are valuable light sources that have no risk of starting a fire or igniting gasses in a mine or on an adventure.¹⁾ It takes 1 turn for a character to harvest all 3 glands from a single beetle.^Ex²⁾ The glands are bulbous, so they have 10 cn encumbrance each.

As opponents

These things can really do quite a lot of damage for a DL 1 creature, and with HD 1+2 and AC 4 they are not one of the easier DL 1 enemies to take down. Fortunately, the light they give off makes them targetable even if the encounter distance falls out of the range of a party's light sources.

¹⁾

The glands are mentioned as being valuable, but no value is given in the books. The gland loses all value if it goes out, as per the d6 day luminosity indicated in the MM entry.

²⁾

DM Note: This is a great special kind of treasure players can look forward to even at low levels, and is an apt reward considering the danger of these beetles.