+1 on what dontavo said but if you really like the eel & would like to give it a try, do make sure you have lids on your tank. In my experience, eels will explore around the tank & will head to the surface when either it gets hungry & it’s searching for food, water conditions are very poor or in the rare occasion that it can’t find a suitable place to claim as its own. Eels need a secure space they can claim as theirs, the reason why some lfs keep pvc pipes in an eel tank. Creating a cavernous space where they can recoil will help it feel secure. Food wise, it depends on its size but I would ask the current owner about his feeding regiment with the eel & continue the same practice. As long as you provide it with an adequate home, water parameters & feeding practices, you will have a happy eel. Good luck.