Name
Salvia: A tall plant in the mint family with purple flowers.
Unyielding Aegis: A name that calls to mind an immovable protector, initially suggested as a joke; at the time, he was recovering from a severe wound and unable to move around, spending much of his days in the same position. Unfortunately for him, some pups overheard his joke, thought it "sounded awesome" and refused to call him anything else. The name stuck.
Lore
0 months: Born alongside a sister and a sibling to Heather, an aloof and antisocial hunter.
1 month: Heather contracts Pox. She moves into the Infirmary while her pups are left in the care of the Pupsitters, who have several other young puppies to care for.
2 ½ months: Heather never fully moves back into the Nursery, and once her pups are weaned, her interactions with them are few and far between. The three youngsters are kept safe and well by the Pupsitters, but none of the adults take a particular interest in them; they become a very tight-knit litter as a result.
8 months: The pups hate that their mother lives in the same pack but barely acknowledges them. Although they express their distress differently - Salvia becomes more brash when she is nearby, in an effort to get her attention - they all wish to be closer with Heather.
Things come to a head when Salvia, desperate to impress his dam, sets out on a solo hunt. He sets his sights on an elk calf, not realising its mother was nearby, and is promptly gored by her antlers.
Thankfully, Salvia's siblings followed him; Liatris distracts the elk cow while Allium fetches help. Salvia survives long enough to be carried back to the Infirmary, where Flurry treats his wounds.
9 months: Salvia slowly recovers in the Infirmary. His siblings visit him frequently, but Heather doesn't make an appearance. Liatris confronts her, and a fight ensues between them before packmates intervene.
Due to her antisocial behaviour, including the callousness towards her pups, Heather is sentenced to spend a month away from the pack; the leaders reason that fending for herself for a while should remind her of the importance of cooperation within the pack.
10 months: Heather's pups decide that they want to distance themselves from their mother by ditching the plant-based names she picked to match her own, giving themselves new ones.
Their packmates are supportive of the idea, giving wildly varying suggestions; the main consensus is that the names should be unique and "have a nice ring to them". After a great deal of thought, the trio decide to take a somewhat nihilistic approach and go with names that don't really make sense, but sound interesting.
Salvia is now well enough to move around, and, growing tired of the Infirmary, he regularly visits the Nursery to play with the pups. They ask over and over to hear the story of his fight with the elk - probably because whenever he tries to explain that it wasn't a fight per se, his siblings chime in to embellish the story; thus, it's told differently each time.
The pups hear one of Salvia's siblings jokingly suggest "Unyielding Aegis" as his new name, and promptly switch to calling him that, and only that. He resigns himself to his new moniker.
11 months: Heather never returns from her temporary exile. Her pups like to think that she's alive, staying away out of shame and living either with a new pack or as a loner. The trio decide to move on with their lives.
1 year: Unyielding Aegis has mostly recovered from his wounds, but still has some scarring along his flank. He also experiences pain and breathing difficulties when exerting himself, which means a hunting role is off the table for him. Thankfully, he already has his heart set on becoming a Pupsitter.
Pupsitter 
Pupsitter