Thank you all for your friendship. Before I met you, I didn't believe in myself. My clan was wiped out by the Metarex. I felt like I was helpless and couldn't do anything to stop them... but because of you, I learned that I didn't have to stand by and watch the Metarex take over. I could do my part to fight back and help restore my clan. I just wanted you to know that I'm happy now because I fulfilled my destiny. Remember, I'll always be with you.

Cosmo is a kind and gentle individual, although she often feels guilt, anger and overwhelming sadness due to being unable to save the rest of her species from destruction at the hands of the Metarex. She also seems to suffer from low self-esteem, often calling herself "unworthy" or blaming herself for the hardships that she and her friends had to endure. Cosmo can be somewhat clumsy, but she is also quite resourceful. She will often rush headfirst into danger with little sense of self-preservation, even into situations that she knows to be a trap, which can be put down to her survivor's guilt spurring her to sacrifice anything to atone for saving herself while her family perished at Dark Oak's hands. Cosmo strongly dislikes violence and the need for conflict in life, like her father in many ways, but unlike him, she acknowledges that fighting is sometimes a necessity and that struggle and conflict are a necessary evil to achieving a better future. Considered by Tails to be "so beautiful", Cosmo is a short and humanoid plant-like alien with pale peach skin and powder blue eyes with one long eyelash on each one. She possesses short bright green hair with a pair of bangs and a paradise pink and rose-like flower bud held by a golden hair tie on the left and right sides of her head. For attire, she wears a long-sleeved dress that has a green blouse bearing golden trim and an ankle-length and petal-like white skirt bearing bright green tips, her mother's Blessed Amulet on her chest, white tights and green ballerina flats.