Technically just one, as long as he's koalafied.
None, there not too bright with doing anything except showing us where to go when were lost in the dark
Two, but you have to get them in the lightbulb first.
Does it have to be a light bulb? I've got this neat candle holder...
Just one. He holds up the light bulb, and the world revolves around him
Only one, given that he's koali-fied for the job.
He wasn't koalafied!
