The cartoonist popularly known as Zunar said the BN version was a distortion.
“A story animation by me has been stolen, changed, edited, distorted and slandered,” he said.
“They won’t be called Umno if they don’t steal someone’s art,” says the staunch government critic.
Zunar said he would discuss with his lawyer on taking legal action.
“I will also report to MCMC (Malaysian Communications and Multimedia Commission) and make a police report.
“This is another false news by Umno and the authorities should charge them under the anti-fake news law. This is the lowest level of plagiarism.”
A pro-BN Facebook page has adapted Zunar’s original cartoon which depicted Najib and his family members pulling a cart.
The modifed animation however showed Mahathir and his family members, riding on a bathtub-shaped cart with the label “22 years”.
Zunar is facing several charges including sedition, over his drawings mocking Najib and Umno leaders.
The cartoonist has also been slapped with a travel ban, and copies of his books had been seized several times.