Hammerhead? What the...?

[BigBoyMS]

This morning I turned on my phone and when the screen came up it was a screen with the green Android robot and since I didn't have my glasses on the only thing I could read was "Hammerhead" near the top of the screen. My first thought was that it had done a reset but I hit the power button and it finished starting into the normal home screen. This is actually the second time in 2 weeks this has happened.
What is this and should I be concerned?

Edit: This is a Nexus 5 with Kit Kat 4.4.2

 

[Golfdriver97]

This morning I turned on my phone and when the screen came up it was a screen with the green Android robot and since I didn't have my glasses on the only thing I could read was "Hammerhead" near the top of the screen. My first thought was that it had done a reset but I hit the power button and it finished starting into the normal home screen. This is actually the second time in 2 weeks this has happened.
What is this and should I be concerned?

Edit: This is a Nexus 5 with Kit Kat 4.4.2

Not sure about what you saw, but Hammerhead is the codename for the Nexus 5.

 

[someguy01234]

Maybe you booted into fastboot mode. It's not a problem.

 

[BigBoyMS]

Yep, I just found that before checking back here. Think I'll check over at Google (Nexus support) and ask why I'm seeing that screen.