If you want to get pedantic about it, "Lego" is a brand, used as an adjective; the toys made under that name are Lego bricks (stylized by Lego Group in official

If you want to get pedantic about it, "Lego" is a brand, used as an adjective; the toys made under that name are Lego bricks (stylized by Lego Group in official material as "LEGO bricks").