I'm not going to answer this one, but may I give a little advice? Be careful not to write a Pokedex Entry, because somebody could easily look it up; You might need to write it in a way that is not a real Pokedex Entry and would therefore be harder. I'm not saying you have written a Pokedex Entry, but please take this note in consideration.
I must catch up with the topics!
What is your favorite Ground-Type Pokemon and why?
That would be Garchomp because it is awesome. But I know I use it too much when I shouldn't, so I tend to have Pokemon such as Rhyperior or Groudon. None the less, Garchomp is a great Pseudo-Legendary, with great speed. Garchomp has a great Move-Set and can learn the ever-powerful move Draco Meteor (Although it is not very good with it, as it is much better at balanced statistics). It can also prove to be a wall at times due to it's decent Defense and Special Defense, making it quite a good wall for it's Speed. It is also a great Physical Attacker (Typically, as it's a Dragon-Type) which makes it very formidable in many ways; But when it comes to need for Special Moves, forget about it, as it is Garchomp's worst Statistic. Also remember that Garchomp's Defenses can still be dramatically lowered, which is when its greatness goes from 100% to about 40%.
But, I also like Rhyperior for many reasons. It's a very superior Pokemon who's Tank has been took up to the next level (Literally) and it becomes almost UNBEATABLE if you don't have any Special Attacks with you. It's what they say - "Never use a Physical Attack on Rhyperior". If you don't defeat IT, it will demolish you. There isn't many Pokemon that can survive Rhyperior's Rock Wrecker easily. The Pokemon that DO survive it are either bad at attacking, or just have high Physical Attack and not Special Attack. Also, due to Rhyperior's high HP, you can't just rely on all Special Moves, you got to rely on the strong ones (Which aren't Electric of course) to faint it. Most tactical Rhyperiors have Focus Sashes so they still have a chance for demolishing your Pokemon. But I have to say, it's Pokedex Entry about shooting out Geodudes is just ridiculous in my opinion. I mean, come on, that's just totally weird. But still, Rhyperior is a good Pokemon for many sorts of occasions, even if you are troubled somewhat by using it. Just don't use it against Pokemon with high Special Attack...
I like Groudon too, but not as much as the others. I don't really think it is the best at... You know, it's Type getting recognized. Many people mistake Groudon for a Fire-Type rather than a Ground-Type. Also, poor Groudon always has it's name spelled wrong! But, hey, don't treat it like a child, IT'S A LEGENDARY FOR GOD'S SAKE. It can learn Fissure... Which makes it very good. It can also be a great offensive Ground-Type, as it learns many elemental moves... Also, it's Drought Ability makes it a very good Tactical Pokemon, has Groudon learns a lot of Fire-Type moves too. Just don't mess with Groudon. It's the strongest Ground-Type (Excluding Ground Arceus), which means it can PWN many other Pokemon which aren't otherwise weak to Ground already. Groudon has an immunity to Electric, what perhaps could be one of the greatest sweepers around, which makes it extra useful. But please don't mention the design... Please...
Ground-Types always live up to my expectations... Always. They made a Ground-Type that dueled with it's duo peer, shaping the land... I wonder what the next Generation (If there will be) has to offer... But for now, only time will tell.