Former Leeds United midfielder Johnson is one of six new arrivals at Carrow Road this summer.
Norwich boss Paul Lambert said: "He has got a little bit of a nasty streak in him.
''He's not over the top - but he won't be shy."
Johnson laughed at his new gaffer's assessment.
He said: "Perhaps it's not a nasty streak - just the desire to win. I have a passion and desire and hopefully Norwich will see the best of me."