Nerin is a s'redit calf.
Like other s'redit, Nerin is gray. He is not the calf of Sanit.
She brought the animals to Valan Luca's traveling show to be performers. Elayne Trakand and Nynaeve al'Meara recognized Nerin, Mer, and Sanit as Seanchan animals and discover Cerandin is Seanchan as well. When the two women leave the show, they offer to take Cerandin as well. She said that she would not leave the circus if she could not take the s'redit as well.