Aesop's Fables are always popular in School Assembly.
Here is a great collection, in pdf format, with links from the index page to take you to each fable.
On each page there are also handy links to hundreds of Values Based Assembly ideas.
Well worth adding to your Assembly Book collection.
Put a copy on your smart phone or tablet and always have a handy Assembly idea with you.
These fables were selected from the Project Gutenberg 1919 version which is out of copyright and in the public domain. The Assembly links go to the AssemblyTube website which is a free website for Assembly Leaders (registration and access is free).