Wai Man Phan Asoon (Teen Hunter)

The sky turns dark and a solar eclipse occurs, signaling a new bad omen for humanity. A terrifying beast, imprisoned underwater for eons, is about to be born into the world from a human womb. Kraisit (Bee-Swiss), a descendant of the legendary Kraithong, knows that Chalawan (the Crocodile King) is being reborn. He steals the infant, seals the evil spirit with an octagonal talisman, and raises the child as a normal human. At that exact auspicious moment, Saengthong (Ae-Rachaya), Kraisit’s wife, gives birth to a son—the reincarnation of Kraithong.
Both Waikoon (Kraithong/played by Petch-Prach) and Navik (Chalawan/played by Khet-Tarakhet) are raised as brothers. Their parents tell them they are twins, yet they share no resemblance. Their personalities are polar opposites: Waikoon is cheerful, social, loves outdoor sports, and is popular with friends, but he fails his exams and is considered a troublemaker. Navik, however, is quiet, introverted, and always top of his class, but has a severe phobia of water. Despite being from different species, the brothers do not fight; they love one another and always help each other in times of trouble.
It is not just crocodiles coming onto land; a mermaid named Mokda (Prae-Waraporn) gets separated from her parents and stranded in the human world. Kraisit, recognizing she is no ordinary fish, teaches her how to transform into a human on the condition that she keeps her identity a secret. She becomes Waikoon's close friend. Meanwhile, Monmai (Sophie-Apsarasiri), a Communication Arts student aspiring to be a professional journalist, becomes interested in Navik's fear of water. She investigates their home to find the truth but is pranked and chased away by Waikoon. In Monmai's eyes, Waikoon is a loser who does nonsense all day, yet he constantly disrupts her life. To make matters worse, Waikoon has a crush on Rungkaew (Fon-Nathida), Monmai’s gentle best friend. Monmai appoints herself "Enemy No. 1" to block Waikoon from getting close to Rungkaew.
As they approach the age of 18, it is predicted that Waikoon and Navik will face a grave misfortune. Kraisit tries to prevent it but fails. During university sports tryouts, a strange incident occurs where Waikoon is nearly severely injured, but Kraisit saves him just in time. Hearing the news, Navik and Rungkaew rush to see him. As they pass the swimming pool, a mysterious force drags Navik into the water. Rungkaew screams in terror. Navik struggles to survive, but the more he fights, the deeper he sinks. As he runs out of breath and nears death, a voice echoes: "Water is life." Navik realizes he can breathe underwater. The force pulling him vanishes, and the talisman on his body begins to glow.
Professor Makorn (Au-Navapol) is actually a crocodile master in disguise at the university, searching for the child harboring Chalawan's spirit—and he has found Navik. However, Makorn's plan faces an obstacle: Yodsinee (Toey-Aratchamon), an heir of the Underworld, is also disguised as a teacher. She is there to drag Chalawan's soul, which escaped 15 years ago, back to Hell, assisted by Than (Porsche-Ariyatach), a Reaper data officer. Navik is torn; he wants to play sports but refuses to abandon his studies. Yodsinee offers a deal: if he can improve Waikoon's grades, she will allow Navik to join Makorn's swimming club.
Waikoon complains about being involved but agrees for Navik's sake. He enters a special tutoring course with Yodsinee, helped by Monmai, Rungkaew, and Navik. Waikoon is annoyed at seeing Monmai every day, but finds relief in the mischievous duo of Tako (Bible-Phupha), Monmai’s 12-year-old brother, and Grandpa Mai Son (Rong Kaomulkadee), Monmai's grandfather who has Alzheimer's and constantly tells supernatural stories. Waikoon enjoys the grandfather's tales, unaware that the stories of crocodiles and mermaids are real and exist right beside him.
Eventually, Waikoon’s grades improve enough for Yodsinee to release Navik to the sports club, though she watches them like a hawk, determined to prevent Chalawan’s rebirth. Knowing he is being watched, Makorn uses his crocodile minions, Wimol (Prae-Praeissara) and Nantha (Grace-Kornkanokporn), to distract Yodsinee and help awaken Navik’s latent powers.
Makorn uses sports to trigger Navik's instincts, giving him superhuman speed and power. However, every coin has two sides; the talisman on Navik fades, and he falls ill, his body beginning to resemble a crocodile. Kraisit intervenes to suppress the transformation and decides to tell Waikoon the truth about Navik’s birth. He puts Waikoon through intense training in the "Crocodile Hunter" arts so he can stop Navik if necessary.
Waikoon endures grueling physical and mental training from Kraisit and Yodsinee to surpass human limits, with Monmai offering encouragement by his side. To fully restore Chalawan, Makorn uses hypnosis to unleash the subconscious locked within Navik. Navik transforms from a gentle man into an aggressive, violent person who hurts competitors. Rungkaew tries to use kindness to bring him back, but Navik goes berserk, kidnaps Monmai, and challenges Waikoon to a swimming race. Waikoon is not ready, still unable to cut the emotional bond with the brother he grew up with.
Mokda volunteers to race instead. Navik refuses to race a woman, sending his minions, but Mokda wins. When Navik breaks his promise to release Monmai, Mokda scolds him. Angered, Navik races Mokda himself. The battle for speed between the mermaid and the crocodile begins. Despite Mokda’s aquatic nature, the Crocodile King is faster; Navik wins decisively and injures Mokda. As long as Waikoon refuses to fight, Navik becomes increasingly dangerous. Even Makorn begins to regret awakening the crocodile instinct.
Before the situation spirals out of control, Yodsinee negotiates with Makorn to settle the conflict. They organize a sports tournament: Waikoon vs. Navik. They will compete in 2 out of 3 sports (Boxing, Basketball, and Swimming) to test their physical skills. It is the inevitable battle between the heir of Chalawan and the heir of Kraithong (2013).
Can Waikoon defeat Navik? Will Navik remain a cruel beast forever? Follow the intensity in "Wai Man Phan Asura" (Monster Generation), airing Monday–Friday at 18:00 on Channel 7. Premiering Tuesday, September 9, 2014.