Millwall have completed the signing of Derby striker Nathan Tyson on loan until the end of the season.
The deal had been agreed on Wednesday and the London club confirmed it has now been sealed.
Tyson is likely to make his debut in Saturday's Championship game with Burnley at The Den.
The 30-year-old will also be available for Millwall's FA Cup fourth round game with Aston Villa on 25 January as he has not featured in the competition this season.
Tyson has scored five goals in 17 matches for the Rams this campaign but will now offer Lions manager Kenny Jackett a further attacking option as he looks to guide his side to the Premier League.