Vanilla the Rabbit

From Sonic - Wiki on Neoseeker

Vanilla the Rabbit as seen in Sonic X

Vanilla is Cream's mother. The name is given in Sonic X; she hasn't been named in the games so far. You see her in Sonic Rush as a person on both Sonic and Blaze's story. She is just a minor character who is unplayable, but she tells you where people just went when someone is looking for them.