Looking on the internet deeply has found these results:

more happy is the most popular phrase on the web.

more happier 160,000 results on the web	more happy 19,900,000 results on the web More popular!
Some examples and use cases from the internet:	Some examples and use cases from the internet:
Nov 15, 2007 ... New York. USA Eng, Haitian Correct. I am more happy than you. Jul 26, 2015 ... I couldn't be more happier than to celebrate this gorgeous #bride to be tonight! # mags2mcd… https://instagram.com/p/5mHnF3LMAe/. 3:14 AM ... WRONG. Anyone remember my tutor? He told me there's no such phrase as 'much more happier, much happier, more happier' or in other words he said it's gramatically ... Creole. I think a lot of people say "all the more happier" and for some reason that doesn't strike me as wrong. Correct. I am more happier ... 'ER' ending and the word "more" together cannot be used. I am happier than you.	There've been stories that l've participated in... or things that have happened, and l've seen them... as a lot more happy things going on in there. You gave me more happy years than a lot of people get in their whole lifetime. And I could not be more happy than being up here alone. You know, it's a good chance for many of them that there'll be more happy times. Looks like it just made her more happy. You'll be much more happy when the war begins. Abby, I've never been more happy to see your gorgeous face. You should find a more happy business.

more happier

160,000 results on the web

more happy

19,900,000 results on the web

More popular!

Nov 15, 2007 ... New York. USA Eng, Haitian
Correct. I am more happy than you.
Jul 26, 2015 ... I couldn't be more happier than to celebrate this gorgeous #bride to be tonight! # mags2mcd… https://instagram.com/p/5mHnF3LMAe/. 3:14 AM ...
WRONG.
Anyone remember my tutor? He told me there's no such phrase as 'much more happier, much happier, more happier' or in other words he said it's gramatically ...
Creole. I think a lot of people say "all the more happier" and for some reason that doesn't strike me as wrong.
Correct. I am more happier
... 'ER' ending and the word "more" together cannot be used. I am happier than you.

There've been stories that l've participated in... or things that have happened, and l've seen them... as a lot more happy things going on in there.
You gave me more happy years than a lot of people get in their whole lifetime.
And I could not be more happy than being up here alone.
You know, it's a good chance for many of them that there'll be more happy times.
Looks like it just made her more happy.
You'll be much more happy when the war begins.
Abby, I've never been more happy to see your gorgeous face.
You should find a more happy business.