The 25-year-old Argentinian donned a mask of the comic book superhero during his time at Real Mallorca, but will not be able to do so in a black and white shirt because of a change in the rules.

He told the club's official website, www.nufc.com: "We can't use it anymore because the rules have changed and we cannot use the mask."

Jonas will not make his Newcastle debut at Hartlepool today as he works his way back to full fitness after his summer break, and will have to wait until manager Kevin Keegan feels he is ready.

However, he is relishing the chance to test himself in the Barclays Premier League as the Magpies attempt to restore their on-field fortunes.

He said: "First, we have to do more than last season, that's very important, and then we have to see where we can finish.

"But first, we have to do more than last season."

Keegan is confident his first summer signing will help the club just do that, while at the same time exciting the fans.

The manager said: "Jonas is the real deal, he is not just somebody who has come and you think, 'He's a bit of a chancer'.

"He is proven and I think our supporters will like him.

"But that's for him to decide by his performances and for them to see how they appreciate it.

"However, Jonas is definitely the sort of player who can excite the fans. I think they will love him for a lot of reasons.

"But the main thing, apart from his pace, is that whoever plays up front will like him because he is a supplier of goals.

"Daniel Guiza, the guy who has just gone to Fenerbahce from Mallorca, won the Golden Boot in Spain, and that means he scored more goals than anyone else at the likes of Real Madrid.

"A key part of that was Jonas and the crosses he provided, and we have got that now."