The DUP will never agree to an Irish language act, party leader Arlene Foster has insisted.
Mrs Foster said if there was to be an Irish language act, there should be a Polish language act because more people in the North speak Polish than Irish.
Sinn Féin have made the introduction of an Irish language act a key demand going into next month's assembly election.
Referring to the demands, she told a party event in Lurgan: "If you feed a crocodile, it will keep coming back for more."
In response to Mrs Foster's comments, Sinn Féin's Gerry Adams joked: "See you later, alligator".
Mr Adams was attending Sinn Féin's candidate unveiling event in Belfast alongside the party's new Stormont leader Michelle O'Neill.
Mrs O'Neill declined to be drawn on Mrs Foster's comments.
"We are not interested in negativity," she said.
"We are fighting this campaign. We have launched our candidates here this morning on the basis of three key principles - respect, equality for all, and integrity in the political institutions.
"That's our job of work, that's what we are concerned with."
Speaking earlier during the launch of the DUP campaign for the 2017 Assembly election, Mrs Foster said Gerry Adams, not Michelle O'Neill, is "front and centre" of the Sinn Féin campaign.
She said: "So concerned were Sinn Féin about their faltering cause that Gerry Adams replaced Sinn Féin's leader with one of his own. Be very clear Michelle O'Neill was selected by Gerry Adams and she will be instructed by Gerry Adams.
"Lets be very clear, at this election Gerry Adams is no longer in the shadows. He is front and centre of Sinn Féin's campaign.
"Come election day, Sinn Féin could have enough seats to become the biggest party. Just imagine what Gerry Adams' radical agenda would mean for our way of life," said Mrs Foster.
She said she understands the anger people feel over the botched renewable heating scheme.
"No one feels worse about what happened than I do. I know for some doubts remain about the scheme and my role in it. I know for my part I have done nothing wrong. I know any investigation will clear my name.
"We all know this election is not about the Renewable Heat Incentive (RHI). The RHI merely gives Sinn Féin the cover to bring down Stormont and force an election when they thought the DUP had been weakened.
"Make no mistake , Gerry Adams is back and centre stage. (Michelle O'Neill) was handpicked by Gerry Adams. She will be there to seek to implement Adams' radical plan ... We are in for the fight our political lives."