Backstory: Though his brother was never afraid of the outside world, Skreg was originally much more careful. Being of the race of small Durri meant that he would make an easy target outside and as such he preferred to stay in. He was more supportive of his brother's outside adventures than pretty much anyone else though, waiting for him at the entrance for long hours and listening eagerly to his adventures. Once his brother proved once and for all that the Durri can live without the protection of their underground tunnels, Skreg ventured out as well. Not long after he came across an injured ironjaw and nursed it back to health, going over and beyond just to hunt enough food for it and treating its wounds so they wouldn't get infected. When a warrior from the wolf clan came by and tried to kill the beast, Skreg stood up against him, almost getting killed in the process, only to be saved by the very ironjaw he saved. The two of them grew attached to each other and now the ironjaw is a loyal and reliable mount to Skreg.
Personal opinion: Out of all the Durri, Skreg is totally my favorite. I relate to him quite a lot from being less adventurous than my siblings and rather playing it safe through still being there for them to welcome them with open arms no matter how strange others think they are to taking care of whoever I can if they need it and going to levels that are not necessarily healthy for me anymore. Skreg is definitely one of the kindest Maulers out there and I appreciate him so much! He's also a huge help on one of my more recent accounts, together with Seirus. His skillset is very convenient and I like that he can't be moved by the enemy, it's a neat little detail!
Headcanon: He feels like the type to push himself to his limits even though he doesn't have to. He probably fell asleep on the way quite a few times because he completely drained his energy. His ironjaw is quite unbothered by it but knows how to tell whether Skreg is awake or not. If he isn't and there's no danger, the ironjaw would try to tread carefully so that he wouldn't shake the tired Durri too much.