From Podpedia

The candle heads are a class of Void Creatures that were tasked to infiltrate and destroy in Sha-Lai. They appeared to have fairly normal physiology up to their nose, where their head ended in a shallow bowl with a little wick and flickering flame. The candle heads appeared somewhat waxen, but seemed to be made of fabric.

In combat, the candleheads were quick and deadly.

A candlehead was the first creature summoned in the attempt to create the void bomb. It proved to be animalistically canny, but not quick witted. It did not know what caused or directed it, only that its nature was to infiltrate and destroy.