Native eels are brilliant pets, caught mine in a river and within a week it was completely tame, have had it inside with the frog for over a year, can hand feed it but tank has moonlighting so prefer to watch it chase down live guppies at night. its strange in that its vision during the day is crap and fish can swim straight past its nose, he will strike at it but miss, night time is a whole different ball game he's lightning fast and deadly accurate, he will chase fish back and forth at speed, can hear him snapping at them on the surface, fish jumping out of the way..its awesome to watch..
Had a larger eel with him recently but let it go after a week because they didn't get on, when larger eel was in tank I would often find smaller eel sleeping/lying on dry land or at the top of the waterfall for hours on end, so don't recommend keeping different size eels together in a small area..