In WW2, in the Pacific, the island called the "Dragon's Tooth" is unbreachable because of a "magic talisman". Rex and Major Dennis raft ashore and see it, the Japanese Emperor's Sword of the Setting Sun that makes the troops invincible. Teaming up, Dennis attacks the troops while Rex steals the sword. Chased underwater, they're rescued by Navy artillery. A Marine notes, "Somebody must've yanked this Dragon's Tooth!"; Rex goes with Danny to a local college to experiment whether animals can think. But Rex smells evil and bolts. He finds a secret lab under the stadium and a hurt scientist. Gangsters stole a "freeze ray" and rob a bank. Rex trips the alarm and leads to their lair. No more tests are needed: animals can think!; In his latest craze, Bobo becomes the mascot of the Eagles baseball team, and best friend of their pitcher, Lefty Crane. When Lefty is kidnapped by gangsters, Bobo tags along, slips inside, and beans them with billiard balls until the police arrive. Bobo even gets his own miniature Eagles uniform!