Warner Bros Japan, on their Twitter page, has posted bios on a few of the creatures of Skull Island. The info is basic but does explain a few things (warning possible minor spoilers). The descriptions are translated from Japanese so they may be off slightly.
Skull Killer/Wing Head
Size: 2-3 meters
Predatory organism resembling a bat. By eating toxic puffer native to the waterside of Skoko Island which will raise the spirit, we further amplify aggression. The aggressiveness of destroying and confusing every life form encountered sometimes kills their own seeds.
About Kong: Skull Island
The producers of Godzilla reimagine the origins of one the most powerful monster myths of all in Kong: Skull Island, from Warner Bros. Pictures, Legendary Pictures and Tencent Pictures. This compelling, original adventure from director Jordan Vogt-Roberts (The Kings of Summer) tells the story of a diverse team of scientists, soldiers and adventurers uniting to explore a mythical, uncharted island in the Pacific, as dangerous as it is beautiful. Cut off from everything they know, the team ventures into the domain of the mighty Kong, igniting the ultimate battle between man and nature. As their mission of discovery becomes one of survival, they must fight to escape a primal Eden in which humanity does not belong.
Kong: Skull Island stars Tom Hiddleston (The Avengers, Thor: The Dark World), Oscar nominee Samuel L. Jackson (Pulp Fiction, Avengers: Age of Ultron), John Goodman (Transformers: Age of Extinction, Argo), Oscar winner Brie Larson (Room, Trainwreck), Jing Tian (Police Story: Lockdown), Toby Kebbell (Dawn of the Planet of the Apes), John Ortiz (Steve Jobs), Corey Hawkins (Straight Outta Compton), Jason Mitchell (Straight Outta Compton), Thomas Mann (Me and Earl and the Dying Girl), with Terry Notary (Dawn of the Planet of the Apes) and Oscar nominee John C. Reilly (Chicago, Guardians of the Galaxy).
Vogt-Roberts directed the film from a screenplay by Dan Gilroy and Max Borenstein and Derek Connolly, story by John Gatins. Kong: Skull Island is produced by Thomas Tull, Mary Parent, Jon Jashni and Alex Garcia, with Eric McLeod and Edward Cheng serving as executive producers.
The creative behind-the-scenes team included director of photography Larry Fong (Batman v Superman: Dawn of Justice), production designer Stefan Dechant (supervising art director True Grit, Avatar), Oscar-nominated editor Richard Pearson (United 93, The Bourne Supremacy) costume designer Mary Vogt (the Men in Black films) and composer Henry Jackman (Captain America: Civil War). The team also included Oscar-winning makeup supervisor Bill Corso (Lemony Snicket’s A Series of Unfortunate Events, Star Wars: The Force Awakens) and supervising stunt coordinator George Cottle (Interstellar, The Dark Knight Rises). The legendary Kong was brought to life at a whole new scale by Industrial Light & Magic, with two-time Oscar winner Stephen Rosenbaum (Avatar, Forrest Gump) serving as visual effects supervisor.
To fully immerse audiences in the mysterious Skull Island, director Jordan Vogt-Roberts and his cast and filmmaking team filmed across three continents over six months, capturing its primordial landscapes on Oahu, Hawaii—where filming commenced—on Australia’s Gold Coast, and finally in Vietnam, where filming took place across multiple locations, some of which have never before been seen on film.
Warner Bros. Pictures/Legendary Pictures and Tencent Pictures present a Legendary Pictures Production, a Jordan Vogt-Roberts Film, Kong: Skull Island. The film will be released worldwide in 2D, 3D in select theatres, and IMAX beginning March 10.