This is an AEC Contour - it is an "Intelligent Object" created by either Land Desktop or Civil 3D. For those without those products, the software can be configured to create "Proxy Graphics" to represent the object. In order to be able to offer DWG interoperability, Bentley preserves these without changing them.
If you save the file to DGN, you can unlock them and drop them and then edit them. I have suggested that MicroStation needs to have that capability while still in a DWG, but as far as I know, that is how these currently function.
Using MicroStation since...
I have never seen anything like this. The problem with it is I can't edit it AT ALL. I cannot drop it, break it or clip it. I just wanted to clip parts of the contours to work with a new design.
Has anybody seen this before and if so, how can I edit it?