do you have any summer fetes/festivals coming up near you? We do quite a few of those and they do have a payback, even if you don't always make big money it is good to get your name out there. At the fetes we do a few of the following.....
(1) guess the weight/name of the bunny (find a cheap big good as new toy bunny that kids can name/weigh off ebay or freecycle). 50p a go.
(2) Pin the tail on the bunny - Again you need a good prize and a photo of a bunny
(3) Face painting - Need 2-3 people quite good at art for this one but the paints (snazaroo) are usually very good value & at a busy fete we can do 100+ kids.
(4) Cookie & brownies - Always go down well & make more profit than big cakes.
(5) Tombola - Put all the really good stuff from your carboot for tombolla. Find some high volume, low margin teddies/keyrings/toys etc to bulk out the prizes.
If you don't have any fetes coming up then organise a collection day with your local council or supermarket. Rumour has it from a man in a dog suit that if you can get a day at Tesco you can with some effort get £500 a day. We have never had a tesco day as you need to apply well in advance but if you are willing to very enthusiastically target the other supermarkets they may let you have a shake a tin day or even a packing day (you'll need a lot of people and tins for that if you do it). Pets at home also let people shake a tin at their store. In all cases you need a "grabber" which will either be photos, a costume (bunny ears?) or something similar.
Use the fundraising section here
I'm sure a donate a vax or some sort of competition would go down well. Every penny counts.
An open day....ok you will need to buy tea/coffee etc but people really enjoy going to see the bunnies.
A sponsor - Do you have a local company/pet shop that might sponsor you?