"A very cautious Pokémon, it raises itself up using its tail to get a better view of its surroundings."
Believe it or not, Sentret was one of the first Johto Pokemon revealed when the region was revealed. Plus, he's one of the first new Johto Pokemon that trainers can catch in Gold/Silver, as they appear right outside of New Leaf Town. Sentrets have appeared on the anime, and between that and the games, they've proven why they're a worthy addition to the Pokemon lineup.
Sentret's Basic Attacks are Scratch and Quick Attack, while its Special Attacks are Grass Knot, Brick Break, and Dig.