Very unlikely to be honest. We know that the vikings traded vast distances and traded with islamic nations to the east and these nations did have trade with madagascar but not until later centuries. The TV show vikings follows the legendary viking; Radnar Lodbrok who lived in the 9th century however the TV series starts with the sacking of lindisfarne at the end of the 8th century. The arabs, who would be the only realistic source for madagascan trade, aren't documented to have started trading settlements in Madagascar until the 10th or 11th century, though they very likely reached the island beforehand.

These Arabs would have come from the south of the Arabian peninsular from the modern day nations of Yemeni and Omen, still very far away from where the vikings commonly traded. I do not know of any sources that would the support he idea of vikings importing tropical animals but I do know of a record of Edgar, King of Scotland gifting a camel to Irish king Muirchertach Ua Briain. however this was also at a later date (1105ad). I think for a late period viking of the 11th century it would be possible though still the journey from Madagascar to Scandinavia would have been a long way to transport a live animal and not something that we have any record of. Perhaps a lemur pelt would be more realistic. So possible but still very unlikely.