The Junimo Plush can only be found in that bush to the north of the playground in the northwestern area of Pelican Town. You’ll have to be there at exactly 12:00pm on the 28th day of a season. Thus far, it’s been confirmed that the plush will appear in both Spring and Fall, with unconfirmed reports of it also appearing in Winter. It’s likely it’s there in all four seasons, but if it doesn’t appear for you in Summer or Winter, that’s likely the reason. Just examine the bush at exactly 12:00pm on the 28th, and you’ll acquire the plush. That’s all there is to it! Credit to Rebekah Valentine on the site https://apptrigger.com/2016/10/13/get-junimo-plush-stardew-valley/.
On the main menu keep clicking on the E in dew evenutally you will see a little alien.
On the main screen click on the leaves, Junimo's should appear.