Robert was voiced by Neil Crone and Robear was voiced by Patrick McKenna.
Robert wears a light-blue shirt and dark blue jeans. It has yet to be explained why Robert's accent is different.
Robear speaks with a French accent, and wears a beret, a white shirt with red horizontal stripes, and blue jeans.
Both of them have pale blue eyes.
The ferrets usually can be seen carrying Stu around in his fishbowl on a stretcher, similarly to how the Ancient Egyptian pharaohs were transported. When his money-making schemes involve heavy labour, they are the ones who do it. Despite all the trouble they go through for their boss, he never sees their work as satisfactory, and they repeatedly get called lazy (and other demeaning terms), are forced to sleep under a rock, and their position as his henchmen is sometimes threatened. When abused too severely, they have abandoned him - even in bad situations - but have always returned due to their loyal nature. The ferrets briefly worked for Iggy in "Fair is Ferret", because he was nice to them. However, he didn't want them stealing things for him from around the park, or tying up the other residents (an acknowledged talent of theirs), so he devised a plan to make them work for Stu again.
Robear's ultimate goal is to please Stu, and he is normally first to compliment him or give him something (which is usually stolen). Both ferrets have displayed a love of stealing on ample occasions. Be that as it may, Robear can also be thoughtful, emotional, and considerate, even going so far as to rescue Zoop from hippos twice in "Oh Brother, Where art Thou?". However, he sometimes puts this alter-ego to work-related use, as in "Scents and Sensibility" (after failing to make a good-smelling perfume for Stu's latest scheme, the ferrets notice Iggy and Jiggers making a perfume for Zoop. Robear then offers them some bottling advice in hopes of getting an opportunity to swap the perfumes). Robert isn't quite as quick-thinking as his brother, and is very timid. Therefore, he usually just does as told, but often spills the beans over something which was supposed to be kept secret.
Deep down they have a strong brotherly love, but their relationship is strained. Robert's stupidity sometimes gets to Robear, and they frequently get into arguments, some of which are physical. Robear will even bang Robert on the head with a hammer if he cheats when they play checkers. He openly admits that he considers himself to be the better of the two in "Koo Koo Achoo". A running gag with them is that they switch positions every now and then. For instance, when in a backhoe together, Robear may be in the left seat and Robert in the right, but if the screen moves to a different shot and then returns, Robert will now be in the left seat and Robear is in the right.
The Ferret Brothers fall into a number of stereotypical categories. They share many assumed traits of ferrets (getting depressed when separated, being afraid of deep water, and seemingly subconsciously snooping through other's belongings and taking whatever their hearts desire). Robear's habit of behaving melodramatically may be an allude to his origins. They are also stereotypical henchmen, in that despite their greatest efforts, they are perpetually in trouble with their boss, and they are poorly educated.