Personally I'm not in favor of cannibalism, at least in my own social circle. But it's pretty common. More than 100 mammal species have been observed to practice it, for example. I wrote about the cannibalistic tendencies of insects, spiders, and even pigs in The Red Hourglass.
Here's a nifty photo-essay highlighting a few notable cannibals of the kingdom.
A Komodo dragon has killed a man on the Isle of Komodo. News outlets are implying that this and another recent death are the first since the 1970s, but there’s reason to believe that attacks like this happen from time to time without getting reported in the West. For example, when David Quammen visited Komodo for his book The Song of the Dodo, he met villagers who’d lost a six-year-old child to a dragon.
The bite of the dragon is both toxic and septic, so anyone who escapes with his life has an excellent chance of dying anyway, unless he’s within reach of a hospital. The venom of the dragon and other monitor lizards is a fairly new discovery, so you won’t find it in my discussion of the dragon in The Red Hourglass. But it is covered in The Book of Deadly Animals, which comes out next spring.