Derived from the wiki:

"Toodles is the youngest of Dandy's World. She often wants to be a part of the fun, and loves proving that she is capable for her ability of helping out!"

Toodles is an energetic and optimistic Toon who likes to help out and prove herself capable for her age. She doesn’t like to admit her weaknesses, such as her fear of the dark, or elevators. She also can be quite curious, and wants to help and doesn’t like when Rodger doesn’t allow her to help him in his cases.

Her voice should be feminine and childish, being high pitched and nasally.