Update tags periodically with json

I tried to find plugins to import json feed to update my tags periodically (let’s say once in a month), but no luck. Here is the case: there is large back-end systems which offers these several feeds to public use. These feeds could contains e.g. animal taxonomy or any other hierarchy. Only some nodes (e.g. all four legged animals) from this hierarchy is needed to import to my tag pool.

Is there any other ways than create my own plugin for this purpose?