Ghana forward Mohammed Kudus left Ajax to join West Ham in a deal worth a reported $48 million on Sunday.
The 23-year-old Kudus joins holding midfielder Edson Alvarez in moving to the Olympic Stadium from Ajax in this summer's transfer window and has signed a five-year deal.
Kudus scored 19 goals and had seven assists in all competitions for Ajax last season, including goals against Liverpool and Napoli in the Champions League.
"I've been dreaming to play in a league like this since I was a kid," Kudus said. "I've been dreaming of this moment and I'm so happy to be here. But it doesn't stop here, I want to keep going.
"I try my best to entertain the fans as I think that's what football is all about. I'm just here to do my best and help the team. I'm really happy to be here. I will fight for the badge. I can't wait to get started."
Kudus has made 24 appearances for Ghana and played at the World Cup last year.
"He's a terrific young talent, who has already shone at the very highest level for Ajax in the Champions League and made well over 150 senior appearances at the age of 23 — so it was no surprise to see so many top clubs chasing his signature this summer," West Ham manager David Moyes said.
West Ham has also signed center midfielder James Ward-Prowse this summer as the club spends the money collected for selling Declan Rice to Arsenal.