This addon is aimed to add simple, but not so boring nautiluses to the game. Now, it features 2 extant nautilus species, the chambered nautilus and the 'fuzzy nautilus'. It also has some additional, experiment-like animals. 

Chambered and 'fuzzy' nautiluses

They

• Spawn in coral reefs (warm ocean) in small groups
• Have 20 health and 2 damage points
• Drop nautilus shells and a few fish
• They have an unexplainable hatred towards tropical fish
• Have baby variants (nautiluses cannot be bred yet)
   
• Fuzzy nautilus is 9 times rarer than chambered nautilus
• There is an extremely rare variant of fuzzy nautilus. It is a fuzzy nautilus with a strange-looking tracker on its back. It's only extraordinary feature is that it drops a torch and some quartz (broken shell) when it dies instead of a normal nautilus shell.

Chambered nautilus

'Fuzzy' nautilus

Baby nautilus size

'fuzzy_nautilus_with_torch'

Spawn egg

Ammonites

• Name a nautilus 'Ammonites'
• Has an appetite for monsters
• Bigger, tougher and stronger than nautiluses
• (Not a nautilus at all)

'Redeye'

• An early ammonites experiment
• Remained in the addon for extra variety
• Hunts monsters in water like ammonites
• Stronger than all other addon-included animals
• Has a regeneration effect
• Name a nautilus after the famous palaeontologist 'Peter Ward'

creator: TheNotSoBigLystrosaurus

Upcoming features:

• Nautilus breeding (the bug is already fixed, will be implemented in next version)
• Sounds

Notes:

Turn on Holiday Creator Features!

First version