All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad is His slave and Messenger.
Any meat of an animal that is not slaughtered according to Islamic rites is dead meat and its parts are forbidden as Allah Says (what means):
{Prohibited to you are dead animals, blood, the flesh of swine, and that which has been dedicated to other than Allah and [those animals] killed by strangling or by a violent blow or by a head long fall or by the goring of horns, and those from which a wild animal has eaten, except what you [are able to] slaughter [before its death], and those which are sacrificed on stone altars.} [Quran 5:3] Allah also Says (what means): {Say, “I do not find within that which was revealed to me [anything] forbidden to one who would eat it unless it be a dead animal or blood spilled out or the flesh of swine — for indeed, it is impure — or it be [that slaughtered in] disobedience, dedicated to other than Allah.} [Quran 6:145]
Besides, Jaabir Ibn ‘Abdullah narrated that the Prophet said on the day of the conquest of Makkah: “Allah has forbidden the sale of intoxicants, dead animals (meat), pigs and idols”. The People asked: “O Prophet of Allah! What about the fat of dead animals for it is used for greasing the boats and the hides; and people use it for lights? He said, “No, it is forbidden”.
Then, the Prophet said: “May Allah curse the Jews, for Allah made the fat (of animals forbidden for them, yet they melted the fat and sold it and ate its price”. [Al-Bukhari]
The Halaal (lawful) meat is any meat of animals slaughtered according to Islamic rites, whether it is slaughtered by a Muslim or by a person from the people of the Book. This ruling applies for the animals which should be slaughtered such as the beasts of cattle and animals hunted from land. As regards what is hunted from water (sea), it does not need to be slaughtered.
Finally, you must remember the ruling mentioned above in Quran 6, verse 145. For more benefit, please refer to Fatwa 81715.
Allah knows best.