Niklus' father was Toots and his mother was Epp. His paternal grandparents were Peeter and Pabbo. He had four brothers and three sisters, named Mikk, Toomas, Paap, Peep, Liis, Mai and Katri. He had a half-brother and four half-sisters, named Tõnn, Tiiu, Mai, Kärt and Ann.