Shiva Purana
राक्षसः कर्कटीपुत्रः कुंभकर्णोद्भवो बली ॥ पीडयत्यनिशं देवान्ब्रह्मदत्तवरोर्जितः ॥ ६० ॥
The Rākṣasa, the powerful son of Karkaṭī, begot by Kumbhakarṇa, harasses the gods always, with his strength enhanced by the boon granted by Brahmā.
english translation
rAkSasaH karkaTIputraH kuMbhakarNodbhavo balI ॥ pIDayatyanizaM devAnbrahmadattavarorjitaH ॥ 60 ॥
hk transliteration by Sanscript