A senior police officer said Bijoy Singh and Bijoy Tanti - both residents of Assam's Cachar district - were arrested from Naxalbari while they were on way to Nepal.
Their local guide Tahidul Pramanik, a resident of Haldibari, was also arrested by the team of police, the officer said.
The lizard, locally known as 'Takshak', was hidden in the jacket of one of the three arrested and later taken to Tukuria range, the officer said.
The lizard, which was suspected to be smuggled into Nepal as confessed by the arrested persons, would have been sold in China market from Nepal for medicinal purpose.