There was once an Inuit hunter, whose name was Oomara. His village was starving, and even he could not find any food to bring back. That night, his son died of starvation. Stricken with grief, Oomara went to bury his son's body, but the ground was frozen so stiff that he couldn't dig a grave. Instead, Oomara left the body outside and decided to wait until morning when the ice thawed.  

Oomara was shocked and scared when he found the bones of his son in the morning, but most of all he was angry. A polar bear cub had eaten his son. Full of fury, Oomara went to a sibyl for help. He asked how to get revenge on the cub. The sibyl answered, and told the hunter to hit the polar bear cub once on the head with one of his son's bones. Oomara returned, and still full of anger, he brought the bone down on the cub's head.  

As the cub lay down dying, a mark appeared where it was hit. A symbol with three lines. 

The Mark of Oomara. 

In The Fire Eternal it is shown that David Rain can turn into Oomara. 

The creepy symbol is found on Suzanna Martindale's arm, on Ingavar's forehead and turns up at the creepiest times possible...

The lines represent Men, Bears and Dragons. In The Fire Ascending it is said to represent Dragons, Firebirds and Unicorns. It is dragontongue for Sometimes, which is Gadzook's favorite word.