I was going to post in my trigger warning thread the rather silly question "Does Winnie the Pooh come with a Tigger warning?"
However I thought before I did that I'd check the phrase on google. I got "about 25000 hits".
I decided to look at some of them. Quite a few are using the pun as I would have and there are a fair number that are clearly typos as "trigger warning" is used elsewhere on the same page BUT there seem to be rather a lot where the "tigger" version is used repeatedly and consistently where it should clearly be "trigger". So, it seems, there are a lot of people out there who genuinely think the phrase is "tigger warning". Bizarre.

Well, pooh!