The comic books giant is preparing a five-issue series spinning out of the “Empyre” comics storyline, with a new crew to battle alongside the Avengers and Fantastic Four.
The team comprising of five members, each representing a different part of the UK, will be led by “Union Jack aka Joseph Chapman”, an existing Marvel comic superhero from England.
Pink-haired and saltire-suited Kelpie is the new Scots superhero, and while her superpowers have not been revealed, Marvel tweeted: “In Scotland, it’s not the monsters you have to worry about. It’s the loch.”
The others include knife-wielding warrior The Choir representing Wales and Ireland's representative called "Snakes."
Although the "fledgling crew" form a strong bond in Marvel world, the new characters have sparked a mixed response.
Scots have since taken to social media to share their views.
One twitter user Fiona McGregor challenged Marvel's announcement saying: "This is disgraceful. You are meddling in politics which you do not appear to understand. Perhaps the ensuing boycott will make the point #indyref2020 #BritNat."
Others have said the idea is "a big mistake" and not a good time to bring out these characters "when our countries are more divided than ever."
Yet other Marvel fans said it is an "awesome" idea and are pleased to see more countries involved in the series.
Written by Paul Grist, the British writer of Judge Dredd, the first issue of “The Union” is out in May.
Mr Grist said: “This is the comic I’ve been waiting 40 years to write.
“New heroes! New adventures! And a team that’s falling apart before it’s even begun!”
Character designer R.B. Silva said: “With Brittania and Kelpie, I wanted them to look like medieval warriors and I just simplified and modernised it from there.
“For Snakes, I thought of the visual for the Executioner. Someone the enemy will fear from just a look.
“And for the Choir, more of a light visual, something that can enable quick movements.
“On her knife I put three dragon’s heads. I know on Wales’ flag they have a dragon with only one head but I thought, why not three?”