Nepali people don’t celebrate April Fool’s day traditionally. We have a fun filled day to celebrate which is an equivalent of April Fool day and is called Gaijatra. But due to the influence of the Western world people play pranks in this day. Many websites have post hoax news on this day and some of the ones I could gather are listed below (there are not many and they are NOT sorted according their wit or excellence).

Gaijatra - Nepali version of April Fool's Day

The Himalayan Times, published a news about a blockbuster Indian movie “Ghajini” to be made in Nepali and will be renamed “Gajendra”. Geetha Arts, the same production house that made Ghajini, will be producing Gajendra, but it will be directed by Narayan Puri, a noted Nepalese film director. That was news! until, the newspaper told later that they forgot to tell the readers that it was one of their April fool pranks.

Mysansar blog published a post showing fake screenshots of chat with Paras Shah (former Nepali prince).

Hamroblog had its definition of April Fool’s day in Nepalese context and a story about it.

Kathmandu Dairies had an article about Nepal Drivers To Switch Sides.

These are few I could gather. Will update as I could gather more of such things. Please leave comment on other sites (Nepali) featuring April Fool pranks.
(UPDATE – Added Himalayan Times news)