I have a branding and marketing agency that specializes in cannabis. We market ourselves as a one stop shop for all your cannabis design/print needs. I just did a pretty big upgrade/update to the entire website.
I want people to go visit the new website. I’m going to create an Instagram post/challenge. The idea is let people know of the upgrade and to go check it out… and the first 5 people to “find” the hidden cannabis leaf gets a 30% coupon on their next project.
Is there a way to create a “hidden” cannabis leaf that will pop up and reveal itself if the viewer clicks on a certain button or image or perhaps if the viewer follows a certain path on the website it will reveal itself?
How hard is this task? Any help would be greatly appreciated, thanks for reading.

How difficult it is depends on how difficult you want to make it. Basically, how hidden is it going to be? Without knowing that, it can be as easy or as difficult as you define it to be.
Basically this is going to take some custom code no matter how you slice it, so how difficult you want it to be is entirely up to you, because somebody has to write the code for it.
Find somebody that knows how to write code for WordPress, and ask them.