This one got me too! My CSM explained to us that this is a test contact that is added to all the portals. We then used it in training to see examples of what logging different activities would look like on the contact timeline, and also use this as an example contact when we test with personalization (https://knowledge.hubspot.com/articles/kcs_article/email/how-do-i-preview-email-personalization). Most of the time we just ignore it, but it has actually been helpful when we need to do some testing (although very confusing to stumble across without notice, I agree!)
I checked internally for you and, as @aliciaw mentions in her post above, "Cool Robot" contact is a Test/Dummy/Sample contact that can get created on your account when setting up tools.
You can either use it to test logging activities for example or, if you don't need it, you can also delete it.
This one got me too! My CSM explained to us that this is a test contact that is added to all the portals. We then used it in training to see examples of what logging different activities would look like on the contact timeline, and also use this as an example contact when we test with personalization (https://knowledge.hubspot.com/articles/kcs_article/email/how-do-i-preview-email-personalization). Most of the time we just ignore it, but it has actually been helpful when we need to do some testing (although very confusing to stumble across without notice, I agree!)