Raja Roy Chowdhury, mostly known by his nickname, Kakababu (Bengali: কাকাবাবু), is a fictional sleuth character created by Bengali author Sunil Gangopadhyay, that has become legendary in Indian children's literature. The series, falling under the adventure genre of literature, targeted at children and teenagers, started in the autumn of 1979 with the publication of Bhoyonkor Sundor in Anandamela magazine, puja number. Since then, the series continued for 33 years on popular demand, with over 36 adventure novels in print until the death of the author in 2012. The publishers of most of Kakababu adventure books are Ananda Publishers, based in Kolkata, India.

Sunil Gangopadhyay or Sunil Ganguly (Bengali: সুনীল গঙ্গোপাধ্যায় Shunil Gônggopaddhae), (7 September 1934 – 23 October 2012)[1] was an Indian poet and novelist.[3] Born in Faridpur, Bangladesh, Gangopadhyay obtained his Master's degree in Bengali from the University of Calcutta, In 1953 he with few of his friends started a Bengali poetry magazine Krittibas. Later he wrote for many different publications.

Ganguly created the Bengali fictional character Kakababu and wrote a series of novels on this character which became legendary in Indian children's literature. In 1982 he received Sahitya Akademi award in 1985 for his novel Those Days (Sei Samaya).[4] Gangopadhyay used the pen names Nil Lohit, Sanatan Pathak, and Nil Upadhyay.[1]

Author of well over 200 books,[1] Sunil was a prolific writer who has excelled in different genres but declares poetry to be his "first love".[5] His Nikhilesh and Neera series of poems (some of which have been translated as For You, Neera and Murmur in the Woods) have been extremely popular.