SB 3.18.22-23

brahmovāca
eṣa te deva devānām
 aṅghri-mūlam upeyuṣām
viprāṇāṁ saurabheyīṇāṁ
 bhūtānām apy anāgasām
āgas-kṛd bhaya-kṛd duṣkṛd
 asmad-rāddha-varo ’suraḥ
anveṣann apratiratho
 lokān aṭati kaṇṭakaḥ
Synonyms: 
brahmā uvāca — Lord Brahmā said; eṣaḥ — this demon; te — Your; deva — O Lord; devānām — to the demigods; aṅghri-mūlam — Your feet; upeyuṣām — to those having obtained; viprāṇām — to the brāhmaṇas; saurabheyīṇām — to the cows; bhūtānām — to ordinary living entities; api — also; anāgasām — innocent; āgaḥ-kṛt — an offender; bhaya-kṛt — a source of fear; duṣkṛt — wrongdoer; asmat — from me; rāddha-varaḥ — having attained a boon; asuraḥ — a demon; anveṣan — searching; apratirathaḥ — having no proper combatant; lokān — all over the universe; aṭati — he wanders; kaṇṭakaḥ — being a pinprick for everyone.
Translation: 
Lord Brahmā said: My dear Lord, this demon has proved to be a constant pinprick to the demigods, the brāhmaṇas, the cows and innocent persons who are spotless and always dependent upon worshiping Your lotus feet. He has become a source of fear by unnecessarily harassing them. Since he has attained a boon from me, he has become a demon, always searching for a proper combatant, wandering all over the universe for this infamous purpose.
Purport: 

There are two classes of living entities: one is called sura, or the demigods, and the other is called asura, or the demons. Demons are generally fond of worshiping the demigods, and there are evidences that by such worship they get extensive power for their sense gratification. This later proves to be a cause of trouble to the brāhmaṇas, demigods and other innocent living entities. Demons habitually find fault with the demigods, brāhmaṇas and innocent, to whom they are a constant source of fear. The way of the demon is to take power from the demigods and then tease the demigods themselves. There is an instance of a great devotee of Lord Śiva who obtained a boon from Lord Śiva that the head of whomever he touched with his hand would come off its trunk. As soon as the boon was offered to him, the demon wanted to touch the very head of Lord Śiva. That is their way. The devotees of the Supreme Personality of Godhead do not, however, ask any favor for sense gratification. Even if they are offered liberation, they refuse it. They are happy simply engaging in the transcendental loving service of the Lord.