A man has been arrested after allegedly attempting to punch the Crystal Palace mascot - Kayla, an American bald eagle.
The 34-year-old has been detained on suspicion of violent disorder and attempted criminal damage. He remains in custody at a south London police station.
Police were investigating fan trouble during the Crystal Palace vs Charlton derby on 24 September.
Eleven others have been arrested and bailed in connection with disorder both inside and outside the ground during the match at Selhurt Park.
A 20-year-old man has been charged with assault by beating.
When Kayla the bald eagle is not attending Crystal Palace games, she lives at the Eagle Heights wildlife park in Eynsford.
Anyone with information to assist the investigation is asked to contact DS Andy Collin on 020 86490111 or Crimestoppers on 0800 555111.
