Weta are a fascinating feature of New Zealand's fauna even more ancient than tuatara and virtually unchanged for 190 million years. Weta became large and flightless like many birds did, in the absence of mammalian predators. There are five groups of weta and we occasionally see the tree weta or the cave weta on our trips. Wetas are completely harmless despite their fearsome appearance. This beast is a giant weta, now confined to offshore islands.