Barubaroi had a very detailed design for a concept monster. Barubaroi had a main head which was shaped like a whale's, and three additional heads on its body's left and right sides. Each head was shaped differently, one of them even having a squid's design. Barubaroi's skin resembles that of Hedorah's and Biollante's, with many eyes barely visible in it. The monster also had a row of plates running down its back, which resemble Godzilla's dorsal plates. It seemed to have a tail the length of Barubaroi's height, which already was noticeably several meters larger than Godzilla's, with a fish tail fin at the end of it. The monster had two legs which it could stand on bipedally, yet Barubaroi's chest had six insect-like limbs which it apparently could use for walking as well.
Barubaroi's role in the film aside from the fact that he would be Godzilla's opponent is unknown. It is possible that Barubaroi changed its appearance throughout the film and that it faced Godzilla Junior, according to concept art. Barubaroi may have had the ability to copy the appearance and traits of other organisms and kaiju, evidenced by some pieces of concept art where it possesses the appendages of various sea animals and resembles deformed versions of Godzilla and Anguirus.
- In a sense, Barubaroi is a prototype for Destoroyah.
- Based on how Barubaroi is towering over Godzilla in concept art, Barubaroi could have been the largest kaiju in the Heisei series.