The vakkibrew is descended from two different types of algae: A long sticky thread-like species, and a floating species that stored waste gases in its tissues to let it stay at the surface. When these entered a symbiotic arrangement (the thread-like species kept the floater tied down in a good habitat, and in return gained the excess sugar from the floater), a new group of plants were born. The vakkibrew could be called the culmination of these. It is 200 metres tall, with the volume of the gasbag being estimated at just under 25000 litres.
During the summer, they will turn pink around the four stalks, from hundreds of tiny ridges in the tree. This is the equivalent of flowers. The second stage of this tree's reproductive cycle is one of the most spectacular events in Klretukpokain's biosphere. In the course of a few weeks at the start of winter, the gasbags will turn shades of amber, red and brown. The gasbags are usually full of hydrogen, but oxygen is added during the colour-change, and on the first full moon a spark (produced by the movement of calcium ions in specialised cells within the sac, which charge up other specialised cells over the course of many weeks) will cause the gasbags with seeds to spontaneously combust. The water particles and burning cinders from the gasbag walls will cause the night sky to tint in the colours of the rainbow, from refracted light hitting the small amount of smoke. Tiny seeds scatter over the area, released during the explosion and with burnt plant matter around them as fertiliser. The tree itself is left with four drooping arms, and a thick green ash-covered casing around the centre stalk, from which it will begin to regrow its gasbag. They will regrow within weeks (although they will be fragile for a few weeks after that), and explode yearly for the rest of their lives.