The National Retail Federation's 2010 Top Costumes survey, conducted by BIGresearch, found that pumpkins are the most popular pet costume choice this year, followed by pumpkin costumes and devil costumes. A dog wearing a Leap Frog Hoodies sold here from Trixie and Peanut is pictured above. It costs $29.
The NRF survey also found the most popular adult and children's costumes. You can find these lists here and here.
Most Popular Pet Costumes 2010
Rank
Costume
%
1
Pumpkin
10.3%
2
Devil
9.7%
3
Witch
5.1%
4
Hot Dog
3.9%
5-tie
Bee
3.6%
5-tie
Cat
3.6%
6
Dog
3.2%
7
Superdog/Supercat
3.1%
8
Ghost
3.0%
9
Pirate
2.5%
10
Bowties/Fancy Collars/Bandanas
2.4%
11
Princess
2.3%
12-tie
Angel
1.8%
12-tie
Star Wars Character
1.8%
13-tie
Batman
1.6%
13-tie
Vampire
1.6%
14-tie
Athlete
1.4%
14-tie
Bat
1.4%
15
Clown
1.3%
16
Spider
1.2%
Other
35.2%
Pumpkin was also the most popular pet Halloween costume in 2009. However, Devil costumes topped the list in 2007.