How do you get the 2017 April Fool's Icon?
It was a mission or event reward. Riot's description in the client reads: “Earned by participating in the 2017 April Fool's event.”
Is the 2017 April Fool's Icon still available?
No. Riot tied the 2017 April Fool's Icon to 2017 (mission reward), and it does not normally bring back past event rewards or bundles.
