Pin the tail on the monkey like suggested, or pin the tail on the giraffe, or tongue on the snake.

If you are hanging crepe paper you could get some coloured cardboard from the shop and trace/cut out some different animals and hang them from above (amongst the crepe paper even) or stick them to the walls etc..

Keep the orange and green theme going with paper/palstic plates,cutlery, cups etc. even balloons, and if you can find some balloons that have pictures of animals on them, you could buy a few and put 1 of each together as decorations, so 1 orange, 1 green and 1 with animals on it.

Get plastic cups, cut out mini animals and when the kids arrive they can pick what animal they want, and then you can write their name on it and stick it to the cup. Or, if you can find some cheapie animal stickers, stick them on some plastic cups for decoration (we did this once with those coloured stars and white plastic cups, kids loved them)

Maybe some paper plates and some crepe paper cut in to strips, a bit of string/elastic/ sticky tape (and pre-cut eye holes) and the kids can make their own lion mask.

Bummer about DD not liking jelly, you could have done the chocolate frog in the pond or stuck some jelly snakes coming out of the jelly.

Print some animal pictures off the net for the kids to colour in.

If the party has to move inside, maybe have a dvd or two, like the lion king, jungle book? ice age.. Some big sheets they can hide under and it can be a "jungle tent"

Get some left over toilet rolls/paper towel rolls and let the kids decorate them with colours,crepe paper, coloured paper, stickers etc, get some masking tape and stick them together, add some string so they can hang it around their neck, and they can have their own binoculars for looking for animals?

Get the kids to guess what the animal noise is, then whoever guesses correctly, can then get up in front of the group for their turn at making an animal noise for everyone to guess.

Have you had a look for any animal/jungle theme party invites? If you can't find themed goodie bags you could get some plain brown paper bags and decorate with stickers, stamps, some of those eyes you stick on and they jiggle around etc.