When he (Aghasura) came and saw Krsna at the head of all the cowherd boys, he thought, "This Krsna has killed my sister and brother, Putana and Bakasura" - SB 10.12.14
Expressions researched:
"when he came and saw Kṛṣṇa at the head of all the cowherd boys, he thought, "This Kṛṣṇa has killed my sister and brother, Pūtanā and Bakāsura"
Srimad-Bhagavatam
SB Canto 10.1 to 10.13
Aghāsura, who had been sent by Kaṁsa, was the younger brother of Pūtanā and Bakāsura. Therefore when he came and saw Kṛṣṇa at the head of all the cowherd boys, he thought, "This Kṛṣṇa has killed my sister and brother, Pūtanā and Bakāsura. Therefore, in order to please them both, I shall kill this Kṛṣṇa, along with His assistants, the other cowherd boys."
Aghāsura, who had been sent by Kaṁsa, was the younger brother of Pūtanā and Bakāsura. Therefore when he came and saw Kṛṣṇa at the head of all the cowherd boys, he thought, "This Kṛṣṇa has killed my sister and brother, Pūtanā and Bakāsura. Therefore, in order to please them both, I shall kill this Kṛṣṇa, along with His assistants, the other cowherd boys."