Murali Karthikeyan Muthuraman, better known by his stage name Karthik, is an Indian actor, playback singer and politician who works in Tamil cinema. He is the son of veteran actor R. Muthuraman. In the 1980s and 90s, Karthik was one of the biggest stars in the industry. He was first introduced by Bharathiraja in the Tamil film Alaigal Oivathillai (1981) and became a lead actor in Tamil films by his own. He has also appeared in some Telugu films where he was initially credited as Murali. Karthik is popularly known as Navarasa Nayagan for his "ability to emote all forms of actions and emotions". He has acted in more than 125 films. He has been the recipient of four Tamil Nadu State Film Awards, a Nandi Award and four Filmfare Awards South.

Muthuraman Radhakrishnan was an Indian actor who predominantly appeared in Tamil language films. He was a leading actor during the 1960s and 1970s and was known as Navarasa Thilagam. He had paired with all the leading heroines of his time and acted in main and character roles. Muthuraman's son Karthik is also a popular Tamil actor and politician, and his grandson Gautham Karthik is also an actor who made his debut in Kadal (2013).