In this paper, we introduce novel miniature swimmers with multiple rigid tails based on spherical helices. The tail distribution of these prototypes enhances its swimming features as well as allowing to carry objects with it. The proposed swimmers are actuated by a rotating magnetic field, generating the robot rotation and thus producing a considerable thrust to start self-propelling. These prototypes achieved propulsion speeds up to 6 mm/s at 3.5 Hz for a 6-mm in size prototypes. We study the efficiency of different tail distribution for a 2-tailed swimmer by varying the angular position between both tails. Moreover, it is demonstrated that these swimmers experience great sensibility when changing their tail height. Besides, these swimmers demonstrate to be effective for cargo carrying tasks since they can displace objects up to 3.5 times their weight. Finally, wall effect is studied with multi-tailed swimmer robots considering 2 containers with 20 and 50-mm in width. Results showed speeds' increments up to 59% when swimmers are actuated in the smaller container.