The boojum evolved from the crawling snark and progressed further inland via Ichthy Swamp and Ichthy River, preferring to live in fresher water, occasionally some rogue/solitary boojum will live along King Coast. They migrate about every 14 months in order to lay and bury their eggs in the coastal waters of King Coast, as well. Their eggs are similar to their snark cousins, just a bit leathery and tougher though still slimy. Young boojum survive by looking very similar to young crawling snarks, as it isn't until they mature that they develop the dorsal sail. Young boojum also usually go for the eggs of crawling snarks, but are capable of attacking baby/young crawling snarks and young beach shrotters. After one mating cycle, young boojum are usually fully mature and follow the adults back to Ichthy Swamp and River. An average mating cycle usually yields between 60 and 95 eggs, of which usually only 24 to 39 individuals survive to maturity.
The boojum, in stark contrast to the crawling snark, is very communal and live in small pods of 5-8 individuals. They are fiercely defensive and protective of not only their own pod but neighboring pods as well. This is helpful in protecting from the occasional harpoon brownble attack. Although they are communal creatures, they are still territorial and will attack any unknown wander boojums that enters into a pods territory that disrupts it's hunting. Swamp boojum rarely get above 1.5 meters in length while river boojum will routinely get to 2 meters in length. Some river boojum individuals have reached almost 3 meters in size, although rarely. Young boojum are vulnerable to the cannibalistic tendencies of crawling snarks, as well as occasionally being prey to an adult beach shrotter.
The dorsal sail is a unique adaptation that allows for greater maneuverability in the water, it also acts as a "solar collector" that helps maintain the boojum's internal body temperature at comfortable levels. This allows the boojum to spend most of it's time in the water, only occasionally going onto land to sunbathe. Another advantageous adaptation is the long nails that have developed on the flipper-feet, these help the boojum dig into the soil to dig up eggs, as well as aids in the digging of their own nests. The nails can also be used defensively or to injure prey, although boojum usually hunt using their jaws.
Artwork by OviraptorFan