This Rhyhorn is a Grace./ -type Pokémon owned by Serena's mother,
After Serena got woken up by Fletchling, Rhyhorn was startled, since Serena made a big fuss out of that. Rhyhorn was used for Serena's training. Grace cheered for Serena, wishing her to do her best. Serena, however, had little control over Rhyhorn and was launched out onto the ground. Serena was displeased, even getting hurt a bit.
After deciding to go on a journey, Serena left the home and bid farewell to her mother and her Pokémon. After Grace visited Serena, Serena remembered practicing Rhyhorn racing, but failed. Serena remembered this event when she fell off Skiddo in a race with her mother, which would decide if Serena would come back home with her mother.
None of Rhyhorn's moves are known.