Pluto was discovered on 18 Feb 1930 and it was a planet for 76 years. In 2006, the International Astronomical Union demoted Pluto to a "dwarf planet," based on some new rules that they thought up all by themselves.
Here are the NEW RULES for those wanting to be a planet:
1. You must be round (in other words, you must be massive enough so that gravity shapes you into a sphere).
2. You must orbit the sun (hence our Moon, which is significantly larger than Pluto, is not a planet, because the Moon orbits Earth, not the Sun).
3. You must dominate the neighborhood around your orbit (in other words, you must sweep up a fair percentage of the asteroids, debris, and comets near your orbit). This is the entirely subjective criterion on which Pluto was flunked out of planet-hood.
Contemporaneous with the discovery of Pluto, Disney's Pluto the Pup was also created in 1930. As a result, there has been some confusion regarding whether the planet was named after the pup. However, as it turns out, Disney's playful pup was initially named, "Rover." It wasn't until 1931 that Disney changed Rover's name to "Pluto." Therefore, the planet was definitely named before the dog, and it is entirely likely that Pluto the Pup was named after Pluto the Planet.
Can you think of anything else that has been named after Pluto? How about element #94, Plutonium? Similarly, uranium, neptunium, cerium, and palladium are all elements that were named after planets. Uranium was named after the planet Uranus. Neptunium was named after the planet Neptune. Cerium was named after the planet Ceres. And palladium was named after the planet Pallas. (Note: Ceres has since been demoted to a dwarf planet, and Pallas has been demoted to asteroid).
(Though lengthy, this video clip is worth watching to the very end, to discover why "your suggestion is rubbish.")