While Griffiths has arrived, Joe Ledley could be on his way out after Celtic manager Neil Lennon confirmed the club had accepted a bid from Crystal Palace for the Wales midfielder.

Griffiths, who arrives for an undisclosed fee, told the club's official website: ``It's been a long time coming. Ever since I heard Celtic were interested there was only once place I wanted to play and I'm just glad it's done now.

“It was the middle of December and my agent gave me a phone and said Celtic could be interested in January and I have just been counting down the days.

“Unfortunately, it’s taken to the last day but I’m just glad that it’s been done now and I can’t wait to get started.”

Griffiths struck 28 goals for Hibernian last season during his second loan spell at his boyhood heroes, and hit 13 for Wolves this term. And he is convinced he can add goals to Celtic.

“I want to bring goals – that’s what I am all about and what I love doing,” he said. “I did it last season for Hibs and have done it for Wolves and now it’s my time to shine in the Hoops and hopefully I can do it.

“I am just thankful to get my chance here and hopefully I can prove that I am a good signing and start scoring goals for fun.”

Lennon is aware that the reaction from some Celtic supporters to the proposed signing was not all positive.

“I think it has been somewhat over the top,” Lennon said.

“He is a young man. He has had a few off the field issues, as we all do.

“Sometimes they get blown out of proportion.

“So I will manage him as best I can and he has to concentrate on his football and if he does I am sure he will be a very good acquisition for the club.

“I have always liked his attitude on the field and having spoken to a lot of people who have played with him and worked with him, managers, they have spoken very highly of him.

“He is an engaging personality, he is quite quiet. Like most people who come with reputations he is not what you would expect.

“He seems quite a focused kid, he knows what he wants and he is delighted to be here. So we are very pleased.

“We think he is value for money. He’s a prolific scorer, knows the environment here and I think we can make him better.”

Lennon revealed his general frustration at trying to do business during the transfer window.

He said: “We put a big bid in this week for a player in Turkey and he couldn’t agree with his club.”

The former Celtic skipper also announced that striker Mo Bangura, who returned to Parkhead at the start of the new year following a loan spell at Swedish club Elfsborg, will leave the club.

The 24-year-old failed to find the net for Celtic in 16 games after signing in a £2.2million deal from AIK in Auguat 2011.

Lennon said: “Mo will be leaving. I am not sure when but he has been given a free, more or less.”