WhatsApp beta users has been testing to send and receive GIF format images/photos. Most of the messenger app supports GIF integration, but so far WhatsApp support GIF has remained stuck to static images.
WhatsApp Support GIF (Updates)
The latest beta release for iOS shows that will likely change soon.@WABetaInfo, which tracks changes to WhatsApp beta updates, notes that version 220.127.116.11 of the app will now autoplay GIF links and embed them directly into your conversations.
UPDATE: GIF support has been rolled to all platforms.