A Hanonian land eel prepares to attack.
The Hanonian land eel is a giant serpentine lifeform native to Hanon IV. Predatory in nature, it inhabits mountainous caverns and ambushes prey that approaches its lair, leaving their bones piled at the cave entrances.
When the crew of the USS Voyager was stranded on Hanon IV in 2373, a Hanonian land eel killed Hogan when he attempted to collect some bones near the cave. Later, a number of Voyager crew escaped from a group of pursuing native humanoids by entering the cave of a land eel, narrowly avoiding being eaten in the process. (VOY: "Basics, Part II")
The Voth scientist, Forra Gegen searched the lair of the Hanonian land eel almost a year later, looking to get genetic evidence to support his Distant Origin Theory from Hogan's remains. (VOY: "Distant Origin")