What they took off him, and what he did anyway

Bait beast

A bait beast is a living practice dummy. It goes in the pit so the properly bred wyverns have something to tear at while they learn, and it is deliberately made unable to fight back — teeth chipped, claws broken, the venomous spikes sawn off the tail. Abraxos was one of the oldest bait beasts in the Fang, which is a horrifying thing to be good at. It means he had already outlived the job by years. When the covens came down to claim their mounts, Manon was owed Titus, the bull bred to carry a Wing Leader. She never got the chance to turn him down. The small scarred one killed Titus first, then looked straight at her, and she said he was hers — the scars, the limp, the burning life in his eyes.

What Manon put back on him

She had the broken teeth pulled and replaced with iron. She had spikes welded onto the tail to give him back the strike his handlers had taken off it. And because his wings were too torn to survive the Crossing, she flew him into the Ruhnn Mountains and bargained her own beauty to a Stygian spider for a bolt of spidersilk — then invented a flaw in the weave to make the thing furious, let it come close, and had Abraxos sweep it off the cliff so she could take the whole bolt. Grafted into the membranes, the silk held. It also left his wings faintly shining in sunlight. Books later, the spider she robbed for those wings is the one that surfaces in the White Fang Mountains and walks them to the Crochan camp.

Flowers

He would not eat the mutton they brought him — fresh kill or nothing. He hated the dark caverns and wanted open sky. And when something small and soft was growing where he could reach it, he stopped and put his face in it. He also would not fly. Manon spurred him at the edge until he panicked, and the two of them went straight off the cliff, and she screamed at him the whole way down to open his wings, and at the last possible second he did. It was clumsy, the wings were still torn, and they flew. Everything between them starts there. Not with the claiming — with the falling. And on the far side of the Crossing there is a meadow, and that is where he goes.

Everything he catches

Watch what he does with the tail they cut. When Manon stands near a drop, he lays it along the cliff's edge — a barrier, on purpose, between her and the fall. In the War Games, Iskra Yellowlegs puts Petrah Blueblood and her wyvern Keelie out of the sky. Abraxos dives after them, Manon leaps across to the dying Keelie and cuts Petrah free, and he catches the pair of them before the canyon walls do. She throws the race to do it and is crowned Wing Leader anyway. At Morath, her grandmother opens her stomach with rusted iron nails and Manon goes over the edge rather than let the old woman finish it. He is already underneath. At Orynth he is wounded and grounded and cannot get to the Thirteen. Afterwards, when she bows over her knees and weeps for them, he lies down beside her and curls that tail around her. Same tail. Nobody taught him that part.