Yes, you can! You can use the Image post-option in Haiilo for creating a post with a GIF. You can upload one GIF per Haiilo post.
For Link and Article type posts, Haiilo does not officially support GIF images, however most of them do play when uploaded in the image field while creating a Link or Article post in Haiilo. It is recommended to use the option 'Upload an image using URL' when uploading GIFs in Haiilo.
GIF images used in Link and Article type posts might play when shared from Haiilo to the social networks but Haiilo does not guarantee this.