hard-shelled (adjective)

1. In Greek mythology, the goddess Athena is often depicted with an owl, a hard-shelled creature, symbolizing wisdom and knowledge.

2. In the anime series Attack on Titan, the giant Titans are hard-shelled creatures that pose a constant threat to humanity.

3. Why don't hard-shelled creatures like to play cards? Because they're afraid of being shellfish and keeping all the aces!

4. During their romantic walk by the beach, they collected various hard-shelled seashells as souvenirs to remember their special day.