What are snails and slugs examples of?

Which athletic shoe brand is named for a small South African antelope? Which word names a small stream and sounds like the noise a squeaky stair makes? A small town is invaded by blood-drinking aliens who look like clowns in which 1988 cult film? What is a glowing, smoldering remnant in a dying fire called? A snake and an experimental art movement founded in 1948 share which name? What word names a sneaker and is also slang for a private investigator? What is a snide, self-satisfied smile called? Which of Snow White's seven dwarfs has a seven-letter name starting with B?