(covers information from several alternate timelines)
When Spock tried to match the sound of the Whale Probe to the sound of an Earth animal aboard the Klingon Bird-of-Prey HMS Bounty, a lion was one of the animals shown on a computer screen. (Star Trek IV: The Voyage Home)
Speaking of his unwillingness to sell his bookstore to make way for the Millennium Gate in 2000, Henry Janeway told Shannon O'Donnel that everyone he knew was ready to feed him to the lions, were they in Roman times. (VOY: "11:59")
The scientific name of the lion as shown on the computer on the Bounty is incorrect. The actual scientific name of the lion is Panthera leo, whereas Vulpes velox stands for the swift fox. The second image shown of the Vulpes velox was of a crab.
In the final draft script of TOS: "Miri", symbolic lions were mentioned, as a stage direction likened a gang of Onlies surrounding James T. Kirk in a classroom to "too many" lions surrounding a lion tamer in a cage.
In the final draft script of Star Trek Generations, William T. Riker mentioned that Deanna Troi was once thrown to the lions in a holodeck promotion ceremony set in ancient Rome (though that line of dialogue wasn't in the first draft of that screenplay).