Kill it with flamethrower and have tek armour and don’t forget element shards to fly! Creative mode use the command killallwildcreatures. It will be ded probably! Back to if survival mode: if flamethrower doesn’t work then use tek sword or any weapon, try using chain bola if it’s a weakness?
When you bring your little lantern pet, or anything that gives off charge, into the area of a seeker, the seeker will double in damage and speed and will aggro towards you until the source of charge has depleted. Oh and they spawn in big numbers, so run for your life.