The Fulham mascot was escorted off the pitch by Foy after delaying the start of the second half on Sunday with his dancing exploits.
It was not the first time the badger has been in hot water this season.
He recently riled Chelsea boss Avram Grant by giving him a hug.
Billy said: “I apologise to Mr Foy. I’m remorseful of my impromptu antics at the Villa game but badgers are hard of hearing and short of sight.
"Had I known that he was about to blow his whistle, I wouldn’t have begun the breakdance routine.
“At the Chelsea game, I just wanted to cheer Avram up as he looked miserable after the first half, although my boss wasn’t sure it did the trick.”
Billy has not been censured by the club and will travel to Middlesbrough for Saturday’s Premier League clash.
He said: “I’ll be travelling on the train where I’ll lead the support of the travelling fans to ensure they get behind the boys, and encourage a performance that will help get us out of the relegation zone.
“I believe that the club can get out of trouble, but it’ll take every Fulham fan getting behind the boys every game to help get the points we need.
“On matchdays, it’s my job to make sure this happens.
“I’ll do my best to behave on both the Fulham Express and at the Riverside Stadium.
“But if Fulham do win the match, I cannot be held responsible for any over-excited breakdancing celebrations that may occur.”