What kind of bug is this?

It's slightly greenish.

Post's pictures

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Sorry, but your photo isn't sufficiently clear to highlight critical bits which would help make a general identification.  The shape suggests that it IS a bug (i.e. Hemiptera) which is the insect order containing shield bugs and the like.  Without being able to see mouthparts, antennal segments and the like it is a bit of a challenge though!