It's possible it is muscovy, muscovy are the main ducks I have experience with and it's possible, but I definitely wouldn't put any money on it. If it is muscovy here is a few things you might need to know.
Muscovy are the only species of domestic duck that is not derived from the mallard duck, they are very quiet and do not quack like other ducks but rather hiss and coo. Male Muscovy are massive, I think the biggest ducks there are. They are generally from 12-20lbs, and the females are less than half of the size of the males, all my females are 5-6lbs. Since Muscovy speak a different language from mallard derived ducks, it is essential to have at least 1 more muscovy to be friends with. They eat kind of a lot, but they are very good for foraging and catching flies and mosquitos. The females are probably the broodiest ducks on the planet, so if you ever want ducklings they are great mothers. It takes about 20 weeks before muscovy are full grown. Also they really are just very friendly, I personally think they are the friendliest duck breed but others might disagree, they also don't lay very many eggs. It should be more easy to tell if it's for sure a muscovy or not in a few weeks, if not it's probably some hybrid duckling.
