Ha - Those are brilliant Ilona Not sure about tigers changing their stripes for spots but hey I really like those tennis balls. Well there is a well known personality whose known as golden balls - but hey these are just brass it has been very cold here recently ;)

And every one said, 'If we only live,
We too will go to sea in a Sieve,---
To the hills of the Chankly Bore!'
Far and few, far and few, Are the lands where the Jumblies live;
Their heads are green, and their hands are blue, And they went to sea in a Sieve.

Edward Lear
http://www.nonsenselit.org/Lear/ns/jumblies.html