Cat7thst is one of Whiteboy7thst's two pet cats. His second pet cat is called NomPopp, where he shares the ownership with KPopp. Cat7thst and NomPopp appear in Whiteboy and Kelly's videos after either being heard meowing, disturbing them while they are recording or being interacted with in certain video. When talking to Cat7thst, not like many YouTuber's with pets, Alex gives Cat7thst his voice, in her own diss video, Rebecca Black Diss Song. Cat7thst has a dark black coat with bright green eyes.
She has her own YouTube channel, where she is starring in a lot of videos; currently 22 videos since February 11, 2011.