Cnidarians: Jellyfish. Do not urinate on the stung though. This will only activate the stingers. Instead cool it in sea (salt) water and scrape away the remaining tentacles (or how you call it)
Answer: Leaves in a cactus are modified into spines to reduce loss of water from leaves by transpiration. Then the plant makes from the process of photosynthesis which is performed by the stem.
