Aniruddha , was the son of Pradyumna and the grandson of Krishna.

2. He is said to have been very much like his grandfather, to the extent that he may be a jana avatar, avatar of Vishnu. The four important Vishnu extensions are Vasudeva, Sankarsana, Pradyumna, and Aniruddha. These four are considered to be vishnu-tattva or Vishnu’s plenary expansions.

3. He is also called Jhashanka and Ushapati.

4. He had a son named Vajra, who later became the King of Indraprastha.

5. Anirudha learned archery from Arjuna.

Source: http://iyadav.com/krishnas-grandson-aniruddha/