When it does, interact with it you will be able to see the option of downloading any additional content right away. There are no pre-requisites, so just keep playing the game and in minutes you will be able to see it in the village. It wears distinct green clothes and has a ‘connection-like’ icon in the map, so you can easily find its location.
You unlock Connecticat very early into your journey, so you just need to progress through the story a little before it becomes available in the first village where you start.
