Wherever there's greenery, there are snails; Taiwan is very green, so the island has an abundance of gastropods. Of approximately 300 snail species and sub-species, 70% are found nowhere else on Earth. At least one of Taiwan's snail species, an invasive exotic, is a major pest (pictured here). While most species are considered inedible, folk in the countryside (including my in-laws) do collect certain kinds for cooking and eating. After the snails are removed from their shells, they're scrubbed with guava leaves to remove the slime. They're then shallow fried with garlic, ginger or basil.
Bats are also common in Taiwan, even in urban areas. Eleven of Taiwan's 35 bat species are endemic. The Bat Conservation Society of Taipei's website has basic information in English plus several photos.
Fishing and changes to the island's rivers (especially canalization and the building of weirs and dams) have pushed 20 of Taiwan's 220 freshwater fish species close to extinction. The country's most intriguing fish is undoubtedly the Formosan landlocked salmon, first described by Japanese scientists in 1917. Two endemic fish species - Acrossocheilus paradoxus (sometimes known as the Taiwan stone minnow) and Candidia barbata - can be seen in Penglai Stream Biological Tour Area (蓬萊溪自然生態園區) in Miaoli County. Visitors can also expect to spot crabs, grey herons and clusters of butterflies.