Agent Rosalie is a naiad in the Department of Misplaced Flora and Fauna. She was described as looking "as if she’d stepped off a painting by John William Waterhouse", and has short brown hair and an easily rattled disposition.
Rosalie joined the PPC in 2008 from an as-of-yet-unknown continuum, and developed a feud with Eledhwen Elerossiel due to the latter's association of naiads with Suvian influence. Rosalie's activity is unknown until shortly before the Blackout, when she was trying to remove a forest from one of the iterations of the Enterprise. Due to malfunctions in the plothole network caused by the Blackout, she accidentally transported the intrusive forest into HQ, and herself with it. When The Doctor arrived, he found Agent Rosalie while looking for the Weeping Angels that had entered HQ and scanned her with his sonic screwdriver. Upon hearing of the danger outside, and possibly also due to Eledhwen's presence with The Doctor, Rosalie stayed in the displaced forest until it was removed from HQ during the post-Blackout cleanup.