SB 6.6.17-18

sarūpāsūta bhūtasya
 bhāryā rudrāṁś ca koṭiśaḥ
raivato ’jo bhavo bhīmo
 vāma ugro vṛṣākapiḥ
ajaikapād ahirbradhno
 bahurūpo mahān iti
rudrasya pārṣadāś cānye
 ghorāḥ preta-vināyakāḥ
Word for word: 
sarūpā — Sarūpā; asūta — gave birth; bhūtasya — of Bhūta; bhāryā — the wife; rudrān — Rudras; ca — and; koṭiśaḥ — ten million; raivataḥ — Raivata; ajaḥ — Aja; bhavaḥ — Bhava; bhīmaḥ — Bhīma; vāmaḥ — Vāma; ugraḥ — Ugra; vṛṣākapiḥ — Vṛṣākapi; ajaikapāt — Ajaikapāt; ahirbradhnaḥ — Ahirbradhna; bahurūpaḥ — Bahurūpa; mahān — Mahān; iti — thus; rudrasya — of these Rudras; pārṣadāḥ — their associates; ca — and; anye — other; ghorāḥ — very fearful; preta — ghosts; vināyakāḥ — and hobgoblins.
Translation: 
Sarūpā, the wife of Bhūta, gave birth to the ten million Rudras, of whom the eleven principle Rudras were Raivata, Aja, Bhava, Bhīma, Vāma, Ugra, Vṛṣākapi, Ajaikapāt, Ahirbradhna, Bahurūpa and Mahān. Their associates, the ghosts and goblins, who are very fearful, were born of the other wife of Bhūta.
Purport: 

Śrīla Viśvanātha Cakravartī Ṭhākura comments that Bhūta had two wives. One of them, Sarūpā, gave birth to the eleven Rudras, and the other wife gave birth to the associates of the Rudras known as the ghosts and hobgoblins.