Its a hujeta (Ctenolucius hujeta) also known as a rocket gar fish - though its not a true gar. They like to be in groups (3+ at least) and require a fairly large tank (48"x18" footprint min) as they can be skittish - also cover up any gaps in the lid, they can be jumpers.
As you can probably tell by its gar like appearance its a predator in nature, but accepts dead food in aquariums. I can even feed mine soft pellet foods. Though to start off I'd start with meaty foods - bits of shrimp, worms, silversides, live blood worm/frozen blood worm etc. One good tip to get them to eat dead foods is to throw a silverside into the current of a filter outflow or powerhead, they think its alive and will strike at it and hopefully eat it. When I first got mine I didn't have a problem getting them to eat dead food. Your title 'And what it eats' suggests your having problems feeding it, I doubt they will accept flake food, they'd need alot of it just to sustain them, I think your best bet would be live blood worm to get them to eat initially. If you're feeding prawn or anyother food too big for them you may need to tear it up, they prefer the smaller thinner strips as its easier to swallow than just lumps as they can't 'cut' their food or rip bits off easily.