I doubt that they thought about the serf one way or the other. The serf was to do the work and didn't require much thought from his master.
A legal conflict between a serf living on a manor with another serf is resolved by the Lord of the Manor or by a court system of sherriffs and bailiffs. Before this, conflicts were settled through parties beating each other.
Some people would say slave, but that is not really correct because a slave could be sold, and a serf could not. Also, a slave had to do whatever told, but a serf simply had to fulfill obligatory duties. A villein was very like a serf, except that a villein lived in town, but a serf was agricultural. A cotter was very like a serf, but we really do not have other information on what a cotter was. It is thought that the cotter was technically free to leave the land, but this is speculation.
Whats serf
The homonym for "serf" is "surf."
Your question is not entirely correct in its premise; a serf is not a slave and does not have an owner. A serf is a subject of a land owner whom the serf would address as lord.
In a feudal system, a serf would remain a serf no matter how hard they were to work.
they where like peasants but lived in the castle to help royalty
Saint Serf died in 583.
Saint Serf was born in 500.
Riddle answer: a serf board.
Peasant/serf