Monty and Vexin have a wonderfully playful relationship. In fact, The Bureau, the group that Iron and Monty work for, is a relatively relaxed location, at least within reason. Off duty, pranks amongst folks are not uncommon, and Vexin specializes in just that. It seems whatever was given to iron has given him springy hooves, springy hooves that sent him bouncing down that forest path.

Monty and Iron are mine.
Vexin belongs to her owner.
And the art comes from  Ratnap