Flybrix is an easy-to-assemble kit that uses LEGO bricks for its non-electronic parts. One kit contains enough parts to let you build a quadcopter, a hexacopter, or an octocopter. Of course, you can also modify it using the LEGO pieces that you already have.
She may not look like much, but she’s got it where it counts. The austere Easy Drone XL Pro can stay airborne for up to 45 minutes per charge and has a maximum capacity of 3lb., so you can use it with MILCs. Its parts fit in a carry-on backpack and can be assembled in a minute.