Various freckle(s) tags:
1 frecklesduo * general
6 freckle * character
1 freckels * general
2 freckling * artist
14 freckle_mcmurray * character
8 freckles_(character) * character
190 freckles_(artist) * artist
3231 freckles * general.
(WP article about skin condition at
http://en.wikipedia.org/wiki/Freckle starts with "Freckles are")
frecklesduo might be accidental combination of "freckles" (the skin condition) and "duo", both of which seem to be in the image in question.
images tagged "freckle" mostly of the skin-condition:
BUT
1) post #351984 (Nsfw) doesn't seem to have any freckles (I see what looks like a beauty mark on face and mole on boob). Character tag of "farah", is the other character named freckle?
2) post #308896 tagged with "freckle" and "freckle_mcmurray". Removed "freckle" from that post with the assumption that the mcmurray tag is the correct one.
3) post #292973 tagged with "freckle" and "freckles". Removed "freckle" tag because already tagged with 3 other character tags (applejack, fluttershy and rainbow_dash) and do not see a 4th character in the image.
4 & 5 & 6)
post #256657 and post #244480 tagged with "freckle" and no other character tag.
post #242636 tagged with "freckle" and character tag "shimavoir".
Freckle skin-condition seems to be present in all three so adding freckles tag.
At first wasn't sure what character name was, but
4-6a) post #242636 "Source:" link points to page at slugbox.deviantart.com which says "I hadn’t drawn Shimavoir or Freckle in a while." so started to think Freckle is a character in the image. A character in image resembles the female character in 256657 and 244480.
4-6b) http://slugbox.deviantart.com/art/Pocket-Monsters-Freckle-and-Shimavoir-307311005 says "KIRLIA - ♀
Nickname: Freckle"
Updated