So in my class, for fun, I let my students write proverbs. I gave them the beginning of the proverb, and then they wrote the rest based on what they thought made sense. Here are some of my favorites. The given part of the proverb is bolded, and how they finished it is in normal font. Enjoy!
Dead men stay under ground.
A friend in need needs a toy.
Barking dogs want sufting. [something... we're working on spelling:)]
When the cat's away the dog is too.
Some other cute ones were:
He who plays with fire is a bad kid who dos'nd lisin to his mother.