What is this instrument???

the one at the begining of this video---http://www.youtube.com/watch?v=WvmgBb7Pimw&feature=BFa&list=FLKg1wn9S0mWI&index=5---the ovious deep sound at the beginning of this one---http://www.youtube.com/watch?v=JpO9xEU6Cy8&feature=BFa&list=FLKg1wn9S0mWI&index=15---and the one that makes the loud! deep! noise in this one at 0.06???---http://www.youtube.com/watch?v=lYlnOtQOQaA&feature=BFa&list=FLKg1wn9S0mWI&index=75