Although lion does not seem to be so important animal, but in Hindu scripture he has a special importance and many mentions.

(1) Lion faced Avataar - Narasinh
The first and foremost important and most discussed lion reference comes in the context of Bhagvaan Vishnu's Avataar (incarnation). He took this Avataar to save His Bhakt Prahlaad and kill his father Hiranyakashyap. This Avataar's name is Narasinh Avataar and it was with lion's head and human body. He had to take this Avataar because Hiranyakashyap had got the boon that he should not be killed by any of Brahmaa's created creature - Asur, Daanav, Gandharv, animal, bird etc etc including human being.

(2) Pratyangiraa Devee
Pratyangiraa Devee is also lion-faced. She is supposed to be the Power of Narasinh Bhagaaan and appeared to pacify him. She rides on a chariot drawn by four lions.

(3) Ride of Durgaa Devee
The second foremost mention of the lion in Hindu scriptures is of lion is as a ride of Durgaa Devee. That is why she is often called "Sheraa Vaalee" - Sher means lion.

(4) Lion-faced Daakinee-Sinhaamukhee
There is a lion-faced Daakinee. In a Tibetan/Indian art museum rmonch (they have a vast collection of Tibetan art) there are various Mandal, Buddha, Daakinee, symbols. It looked like a sacred art work displayed just for mere enjoyment. There was a striking red naked Daakinee with Lion face displaying her majestic teeth as bright as the Sun. One visitor reports that "after seeing this image more unusual things happened in my personal life." The Daakinee's name is Sinhaamukhee.