She is a red porcupine whose quills are full of white flake-like dandruff, thus her name. She is one of the most popular characters in the series and she has the identifiable personality of a very cautious and timid character.
Early on, Flaky's gender was never made clear due to the lack of distinctly feminine traits in her physical appearance, which often led to confusion to whether she could be identified as female or otherwise. This confusion was hinted as a gag later in the series, with her gender being left as ambigious. Though initially designed as male by series creator Rhode Montijo, Flaky is repeatedly hinted to be female according to comments by most of the series' staff, with some either leaving it up for interpretation or keeping it anonymous.
Happy Tree Friends characters: