For some reason my friends hen night theme is 'cartoon characters'.  I have zero imagination when it comes to these things - any ideas ?

How about one of the disney princesses: Belle from beauty and the beast, Snow white, little mermaid (I went as her once), Jasmine (Aladin)
Or a smurf (smurfette- blue facepaint, white clothes, blonde wig [unless you are blonde])
Powerpuff girl
One of the scooby gang
One of the flintstones
Batman
Johnny Bravo

http://www.allfancydress.com/Fancy-Dress-Costumes/613/General.aspx

http://www.joke.co.uk/fancy_dress/adult_looney_tunes_characters_his_and_hers~1150/index.html

MiNnie Mouse is easy to do and can be dressed up or down to suit how adventurous you are feeling :-)

Any of the Disney princesses should also be easy(ish) to cater for and also Poccahontas (sp).

You could maybe go for something a bit different like Roadrunner , Bugs Bunny sort of thing? But girly it up a little bit!! :)

Spongebob Squarepants. :-) I admit I am a spongebob lover, I love that programme, there are all the other characters from the show too.

how about peppa pig,horrid henry,dora the explorer?
or one of the mr men or little miss?