The huge drone that Preston Stormer fights in the flashback scenes was actually designed by a fan for Official Bionicle Building Contest #53, which was held on the LEGO fansite BZPower.com. It was revealed early on that the winner model will have a special purpose, but this was kept secret until the cartoon aired.
Several characters that appear in the cartoon are not based on existing LEGO models. Professor Zib and his floating helper Quadal are prominent characters despite not having toys to promote. Sir Makuro, the giant evil drone, the female reporter, and a bunch of other side characters also belong to this group.
The name of Makuhero City comes from a play on the expression "make you a hero". This is fitting, considering the city's primary facility is the Hero Factory. It also references its founder, Akiyama Makuro.