Tubal

Tubal son of Japheth and Grandson to Noah

Gen 10:2  The sons of Japheth; Gomer, and Magog, and Madai, and Javan, and Tubal, and Meshech, and Tiras.

1Ch 1:5  The sons of Japheth; Gomer, and Magog, and Madai, and Javan, and Tubal, and Meshech, and Tiras. 

Here it refers to his the tribe of his people (Italy)

Isa 66:19  And I will set a sign among them, and I will send those that escape of them unto the nations, to Tarshish, Pul, and Lud, that draw the bow, to Tubal, and Javan, to the isles afar off, that have not heard my fame, neither have seen my glory; and they shall declare my glory among the Gentiles. 

Listed with his brothers as merchants

Eze 27:13  Javan, Tubal, and Meshech, they were thy merchants: they traded the persons of men and vessels of brass in thy market. 

Speaking of the Scythians, a powerful and warlike people; and all their armies.

Eze 32:26  There is Meshech, Tubal, and all her multitude: her graves are round about him: all of them uncircumcised, slain by the sword, though they caused their terror in the land of the living. 

Is it speaking of the land or the people?

Eze 38:2  Son of man, set thy face against Gog, the land of Magog, the chief prince of Meshech and Tubal, and prophesy against him, 

Eze 38:3  And say, Thus saith the Lord GOD; Behold, I am against thee, O Gog, the chief prince of Meshech and Tubal:

Eze 39:1  Therefore, thou son of man, prophesy against Gog, and say, Thus saith the Lord GOD; Behold, I am against thee, O Gog, the chief prince of Meshech and Tubal: