Alderheart is a sturdy[19] dark ginger tom[1] with a white-tipped tail,[20] and amber eyes.[1]

Alderheart serves ThunderClan as a medicine cat under the leaderships of Bramblestar, Tigerstar, the impostor, Lionblaze, Graystripe, and Squirrelstar in the lake territories. He was born as Alderkit to Squirrelstar and Brambleclaw, alongside his littermates, Sparkkit, Juniperkit, and Dandelionkit. Initially apprenticed as Alderpaw to Molewhisker, he later chooses to be a medicine cat apprentice.