Free Alistar https://leagueoflegends.com/youtube
The above link should work fine for any server. Just in case it doesn't . Below are some server specific link. I used the link to get Alistar on Eune . I was logged in my lol account first.
North America https://na.leagueoflegends.com/facebook
Europe West https://euw.leagueoflegends.com/facebook
Europe East https://eune.leagueoflegends.com/facebook