"That is one of his many practical jokes" is just a statement, neither an adjective nor a proverb, although the words many and practical are both adjectives.
many
One, many, and practical are all adjectives
many
It means that people who pull practical jokes on other people or enjoy it when they occur don't have the right to get upset when someone pulls one on them.
One can find joke about the causes and symptoms of IBS on sites like all jokes, heel that pain jokes, jokes forever, million jokes, jokes for life and many more.
Only one.
One can find jokes about burning feet by running across hot coals on sites like all jokes, pain jokes, million jokes and many more. One can also find jokes from joke books which one can find at retails stores.
Wanda makes many jokes. One of Wanda's jokes is about farting.
Corny jokes many be found at the Funny or Die website. One may also find corny jokes at A Corny Joke a Day, Iowa Source, Great Clean Jokes, The Oatmeal and Fat Wallet.
Punjablinks is a website that features many types of Punjabi jokes. Some other sites that have these kinds of funny jokes are Funenclave and Ludhianaonline.
One can read lawyer jokes at a variety of different websites including Jokes, Jokes Gallery, and Jokes Warehouse. One can also look through joke books at one's local library.