This is the Shocked Face emoji.
There is also this OMG! emoji on the "[more]" popup window.
Regarding your font changing when you hit backspace. I never have that issue, nor can I replicate it. The only way I can see the font "changing" when you backspace is if you backspace across the transition from one font to another font. This is not really changing, but only picking up the font type at the point you stopped backspacing. One easy way to avoid issues is to type your message and make your font changes at the end. You have to really be careful if you cut and paste text of various font types around in your post. This can start to confuse the editor. The best thing is to keep it simple. Making font changes at the end will prevent any issues.
FWIW AJ, happens to me too! I finish the text. Then go back and edit, or backspace, maybe add a comma, or something, and the rest of the sentence in the paragraph shrinks the size of the letters. Then, when I actually post it, it say that 78% stuff, that I don’t understand.
Not that big a deal to me, but if it’s correctable, that would be cool!
Rush