Is Neptune a cannibal planet?

It would explain a lot if the blue gas giant swallowed another planet twice the size of Earth once upon a time, and stole its moon- Triton.

Neptune and Uranus are huge- which is hard to explain if they formed where they are now, in the material-thin outer reaches of the solar system. Scientists reason that they either formed closer to the Sun and drifted outward, or absorbed other, smaller bodies. And Triton orbits Neptune in the opposite direction from the planet's rotation, which can most easily be explained by its having been captured by Neptune rather than originating with the giant blue planet.