Puzzle #1

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Across
  1. 1. Intelligent sea mammal
  2. 4. Master of the skies
  3. 8. Playful river swimmer
  4. 9. Armor-plated crawler
Down
  1. 2. Stealthy jungle cat
  2. 3. The unicorn of the sea
  3. 5. Nocturnal tree dweller
  4. 6. Sleeps up to 20 hours
  5. 7. Long-legged wading bird
  6. 10. Watchful desert sentinel