Of course Fiona has her own name authority record!
Following RDA 9.6.1.8, the name authority record for Real Non-human Entities should have a designation for type, species, or breed, in this case “Hippopotamus”:
368 ǂc Hippopotamus ǂ2 lcsh
Following RDA 9.19.1.8, the authorized access point may include such a designation to distinguish from access points for people with similar names:
600 00 ǂa Fiona ǂc (Hippopotamus), ǂd 2017-
The longest shot : Lil E. Tee and the Kentucky Derby / John Eisenberg. (OCLC #897135902)
The subject heading for the racehorse Lil E. Tee (winner of the 1992 Kentucky Derby) was established as a (topical) subject heading:
150 Lil E. Tee (Race horse)
which is odd. The section of the Subject Heading Manual on “Establishing Certain Entities in the Name or Subject Authority File” says that Named Animals should be established as a name authority, specifically in a 100. The record was entered in 1995, around the time that these distinctions were in flux.
A search in the name authority file for “race horse” only produced about 13 headings of that form (like Man o’ War (Race horse), 1917-1947), but the search for that phrase in topical headings produced close to a hundred headings (including Barbaro (Race horse), born 2003), so there is still inconsistency in how these are being established.