It is very easy to earn the reputation of a mooch. It’s very hard to get rid of it.
One can be a mooch with time, too. Be the person that occasionally is at their desk until 5:15 or 5:30, not the person who starts packing their stuff up at 4:58 to absolutely, every day, be gone at 5:00. Be flexible giving time and nobody will care when you take some. Never, ever give time and get a reputation as the person who never does anything extra, even if everyone is working the same number of hours.