mountoff

A simple slash-command to mount the same mount as your target, if you have it.

Usage: /mountoff [help]

To copy your target's mount:
/mountoff

To view the help message:

/mountoff help

Integrated with a flying/ground/aquatic mount macro (will cast target's mount if you have a mounted target):

#showtooltip /mountoff /cast [swimming] Subdued Seahorse /cast [flyable] Heavenly Azure Cloud Serpent /cast [noflyable] Green Skeletal Warhorse

Uses the new C_MountJournal API functions. Possibly not compatible with versions earlier than Legion. Confirmed compatible with Battle for Azeroth.

Feel free to post any bugs, suggestion or problems in the comments below.