It is born with a wondrous power that lets it bond with any kind of Pokémon.
– Pokemon Platinum Pokedex
Manaphy is kind of an annoying legendary to obtain, because it’s not in an of the main games. It can be obtained from Pokemon Ranger, or from a few events. I often forget about Manaphy when thinking about legendaries. It’s unique as a legendary in that it can be bred with a Ditto, but the resulting Pokemon will be a Phione instead of Manaphy.
In the anime, Manaphy is featured in the Pokemon Ranger movie. Despite Manaphy being a 4th gen Pokemon, the movie is considered an Advanced movie featuring May and Max. In the movie, May befriended a Manaphy.
Stat-wise, Manaphy has 100 in every stat, making it very versatile. It also has access to Tail Glow, which only few Pokemon can learn. Tail Glow raises Sp Attack by 2 stages in Gen IV and 3 stages in Gen V. Its exclusive move, Heart Swap, is not an attacking move, but a status move (and not a very useful one in most situations imo).
p.s. sorry for the last post, I forgot I didn’t schedule a post