Looking at the colours, I'd say they look more like Moominpappa and the Joxter, instead of their sons. Though, I've only ever watched one of the TV adaptations, so I suppose these could be from another show?
Actually, I'm not so sure about this one. Only Joxter is supposed to have a red nose, but he also has a red hat. The character seems to be some kind of mash-up of Joxter and Snufkin, at least according to his accessories.