'Wild' imagination

Just surprise them! Say "Shall we go for a walk in the jungle?" and let your and their imagination take you on a wild safari adventure! Fight your way through the long grasses, trudge through swamps, run quick when there's a tiger coming... Getting hungry? Why not climb this banana tree and pick some bananas, put them in your back pack, climb back down again... I could go on... but that would be getting carried away!
The possibilities are endless...

[Ruthierhyme]

This would be a great idea for a planned physical activity - adapted slightly it could be used along the lines of 'we're going on a bear search'.

In the gym/playroom or in the playground, large pictures could be held up for the children to change tempo/actions whilst moving around the open space -

For stamping feet and arm swinging trunks!
Hissing snakes winding their way over the floor!
Monkey's swinging from vine to vine
Crocodiles - with arm snapping jaws.
Lions with prowling roars, stalking through the grass.