Cree Summer (born Cree Summer Francks on July 7, 1969) is an American voice actress. She is best known for roles such as Penny on Inspector Gadget, Elmyra on Tiny Toons, Hyena on Gargoyles, Susie Charmichael on Rugrats and All Grown Up, Foxxy Love on Drawn Together, Numbuh 5 on Codename Kids Next Door and as the voice of the Green M&M. On an unrelated note, she also voices Medusa from Kid Icarus, an awesome game that no one plays. Pity.
Along with Tara Strong, she is essentially one of two women doing every female voice in cartoons today. (Okay, Grey DeLisle is getting there too...)