This is one of my favourites. It flows smoothly, makes a point and is, I think, elegantly simple in structure. Some have said that the last stanza is redundant and could be removed. Currently I favour keeping it as I don't think the metaphor is totally clear without it.
There is a tiger watching me,
circling slowly around,
and padding about.
There is a tiger watching me,
I can't see,
but I know without doubt.
That there is a tiger watching me,
coming closer today,
am I friend or prey?
Oh yes there is a tiger watching me,
It is hidden,
just out of sight.
The tiger watching me,
passes judgement,
but never does shout.
And the strangest thought of all,
is that it just could be,
that the tiger is me.