Images are from medieval manuscript:

Monkeys & human from the Book of Hours, Use of Maastricht (Stowe MS 17)

Plants from A collection of medical texts including Tractatus de herbis (Egerton MS 747)

The song is: It Had Better Be Tonight (Meglio stasera) (From the Mirisch-G & E Production The Pink Panther)

They were animated using Adobe After Effects and the plugin DUIK

A couple draft walk cycles: