Escherichia coli bacteria, when viewed under a microscope, typically appear as short, rod-shaped cells.

Here's a more detailed description:

* Shape: Rod-shaped (also called bacilli)

* Size: About 2-3 micrometers long and 0.5-1 micrometer wide

* Appearance: Often described as being "short and plump" or "sausage-shaped"

* Other features: They may appear singly, in pairs (diplococci), or in chains.

Keep in mind that the exact shape of bacteria can vary slightly depending on the specific strain and environmental conditions.