whats is that on my puffer? pics

I can't really say what it is. Fish can be bruised, though, just like other animals with blood moving through a vascular system. This doesn't look like a bruise, though. How long has it had it? Changes to the appearance? Tank conditions and mates?
 
i had for almost a week.. no other changes to it, it mite have lighten in color.... but other then that no... a snowflake eel and a hawk fish
 
Could just be normal coloration. Some types of puffers do have rings around their eyes--pandas, for example. Many change color as they mature, and can look pretty blotchy during the process. What species is it? Eating normally?
 
Dogface isn't specific, it's used to identify a number of fish that have the same basic body plan. Could be a blackspotted, as that's the most common one sold as the dogface. If that's if that's the case, the color patterning is very common, and variable, depending on where it came from.
 
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