Goblin names are given to the player by goblin guards during the questLand of the Goblins. When talking to them after transforming into a goblin, they will try to guess your goblin name.
If players don't like the goblin name they're given, they can ask the goblin guards to guess their name again to be given another name.
List of possible goblin names
The name is a random combination of a prefix and body part. There are 31 possible prefixes and 32 suffixes, for a total of 992 possible names.