1. The Lorax

Via yandy.com
2. Big Bird

Via yandy.com
3. Strawberry Shortcake

Via halloweencostumes.com
This is billed as a "Sexy Strawberry Dessert Costume," but the source is clear.
4. My Little Pony

5. The Grinch

Via yandy.com
6. Rainbow Brite

Via halloweencostumes.com
This one's called "Sexy 80s Rainbow Vixen."
7. Cheshire Cat

Via yandy.com
8. Cookie Monster

Via yandy.com
h/t Jessica Valenti.
9. Tweety Bird

Via costumesupercenter.com!{ifpe:pe}{ifpla:pla}!{keyword}!{matchtype}!{adwords_producttargetid}!{network}!{ifmobile:M}!{creative}&CAWELAI
10. Ninja Turtle

11. Power Ranger

12. Ursula the Sea Witch

13. Glinda the Good Witch

14. Kermit the Frog
