Cosmo the Seedrian

Cosmo is a good friend to Sonic, Knuckles, Tails and the others. She sacrificed herself in season 3 episodes 77: A Fearless Friend! and episode 78: So Long, Sonic!. She will also return in Sonic X season 4 episode 79: The Return of Cosmo. She is voiced by Amy Birnbaum, who also voices Froggy and Metal Cosmo in the series.