Use any Drake or other flying mount that have loud /mountspecial sound.
To annoy the people do the following.
Bind /mount special, spam it and move a bit. Keep doing it and sound will keep repeating from start, you can annoy the f*** out of people.
Mounts that can spam /mountspecial without moving are [Obsidian Nightwing] and [Sandstone Drake].
Have a fun.