what is this on my oscars Head?!

  • We are currently upgrading MFK. thanks! -neo
idk but seems painful
 
The red part's just irritation. What's causing the irritation is his case of Hole In The Head. Better get to researching and changing water :-)
 
Right. His tissues are eroding around his nostrils from HITH and the erosion has reached a sensitive spot, or gotten infected...
 
MonsterFishKeepers.com