Hunter De Vil is the chief antagonist in 101 Dalmatian Street, serving as the main antagonist in Season 1. He is a photographer and the great-nephew of Cruella De Vil. He's full of schemes to get popular on the internet, and finds that his best bet is taking pictures of rare/cute animals.
Hunter is stocky with very thin legs. He is blond with an undercut hairstyle. He wears a red jacket over a white shirt and a black tie. He wears black pants and gloves, and red sneakers.
As being the main antagonist of the first season, the actual main antagonist would appear in the finale of that season.
In the episode "London, We Have a Problem", it is revealed that the main antagonist is, very probably, Cruella de Vil, who is still alive and living in Switzerland. Hunter follows her orders to kidnap the dalmatian family.
It is currently unknown if she actually retired from capturing dogs though. But again, she might be the main antagonist of the series. Maybe not because she might have retired.
If a future episode confirms Cruella to not be the main antagonist, then the actual main antagonist will be a surprise.