Rope fish

[thefishofdoom]

i have one and its not true that they wont eat anything bigger than a guppy mine eats feeder gold fish. and they can get 20in i think

 

[Gooda]

Any fish with a built-in teleportation device is quite good at escaping from a tank.
Laser glass-cutting tools help too.

It would also need to be really good at self defence because after it cuts a hole in the side of my tank we are going to brawl.

 

[mcblack]

the same care to be given to like bichirs, cover your tank properly because their escape artist, they eat mostly anything that fits their mouth, their nocturnal fishes, they hunt usually during the night

 

[guppy]

They will eat fish up to the size of giant danios, trust me on that one. It was around 20" at the time, supposedly they can reach 36"(according to fishbase) but I have never seen one that size. They are not aggressive but they are carnivores. If the fish is active and bigger around then it's head it should be fairly safe. They are not quite as good at getting out as american eels but it is close.