"Manoj Tiwari has adopted Urvashi, a nine-year-old lioness in the zoo at a simple function, " said Abhay Kumar, a zoo official.
Kumar says it is a matter of pride that Manoj has adopted a lioness, while another Bhojpuri film actor Ravi Kishan is likely to adopt a chimpanzee soon.
Tiwari says he adopted the lioness as part of his effort to raise awareness among people about animal conservation.
"I will help to spread awareness about endangered animals, " Tiwari told reporters.
Last month, the Bihar government launched the 'Adopt an Animal' scheme at the zoo, following which about 100 animals, including birds, have been adopted by people, organisations and companies.
The adopters were given a memento and a certificate by the zoo authorities.
Under the programme, animals can be adopted for a period of five years to a month by paying a fee, according to a zoo official.
The whole zoo can be adopted -- but only for a day.
"The fee includes the food and medical cost of animals. Under the scheme, a sign board with the company's logo or the name of the person adopting the animal will be displayed outside the enclosure, " the official added.
The Patna zoo is one of the 21 large zoological gardens in India and the only one in Bihar. There are about 1, 200 animals and birds in the park, which is spread over 153 acres.