KAMPUNG KOMODO, Indonesia -- At least once a week, an unwelcome intruder crawls under a clapboard wall and, forked tongue darting, lumbers its way into Syarif Maulana's classroom.

"Then, everyone screams, there is no more school, and we all run away very fast," says the 10-year-old boy. "We are very afraid."

The intruder, a Komodo dragon,...