Toad
A toad was an amphibious creature. Its name could also have insulting connotations.
In 2268, Stella called Harry Mudd a miserable, conniving toad. (TOS: "I, Mudd")
In 2366, Lwaxana Troi called DaiMon Tog "a toad-faced troll". (TNG: "Ménage à Troi")
In 2369, Kolos called Quark an obsequious toad. (DS9: "Q-Less")
In 2370, Kira Nerys seethed, "That little toad [Quark] is this far from doing a 360 out an airlock!" after he had complained to her about Varani's music causing him to lose profits. (DS9: "Sanctuary")
In the mirror universe that year, Kira told Benjamin Sisko that "a Ferengi toad named Quark" was the only caring person she had met on Terok Nor. (DS9: "Crossover")
In 2371, having merged with Curzon Dax, Odo described Quark as "that little toad". (DS9: "Facets")
In 2372, when speaking to Jadzia Dax, Kor called Quark a toad-faced Ferengi. (DS9: "The Sword of Kahless")
In 2373, Q called Q a "two-timing toad" when he vanished into the Q Continuum with Kathryn Janeway. (VOY: "The Q and the Grey")