I think the warning might have to do something with rover. Maybe the skull face showed up because it meant he was dead. Also since the Viking helmet was red than..... I forgot who had the helmet but that again points to rover I think. Since rover's color was red, I think it has something to do with it. Maybe it means something like since rover was not a good leader, the others who take after him die? I just guess that because the first penguin was red with a red Viking helmet, and then the blue one with a Viking helmet(I'm guessing a follower of rover) died because he followed rover. I hope this isn't too complicated. This is my guess.

Detective Frogs

Edit: Sorry for making it so complicated. I'm basically trying to say that the red penguin is rover, and the blue penguin took after rover. But since rover died, since he wasn't bad enough, those who took after him also died. That's what the skull was for.

Detective Frogs

I'm not quite sure what your saying. Well done for trying to solve it! You must be good, it's too complicated for me... -Archie

This case is still going on? I think Damen or the person who made it up should tell us now because it's getting really annoying that people are telling us theory's when we could be viewing other things. I don't want to sound mean and all you ideas and explaining is great, but i think it's enough cases for me.