Here are five things bundesliga.com thinks you should know about the league's latest Belgian arrival as "Batsman" replaces "Batman" in Dortmund.
1) Not your standard footballer
Batshuayi was born and brought up in Brussels and spent a season at local club Anderlecht before breaking through at the home of their great rivals Standard Liege. He scored his first goal for the club as a 17-year-old – the only strike in a UEFA Europa League win against Copenhagen in December 2011.
As a 20-year-old he came agonisingly close to winning the Belgian title, scoring 21 goals in the 2013/2014 campaign only to see his side lose out to Anderlecht on the final day. Batshuayi was also named as the best player of African descent in the Belgian Pro League that season.
His younger brother Aaron Leya Iseka – who played against Dortmund in a friendly in January – is still in Belgium, on loan at Zulte Waregem from Anderlecht.
2) Moving on up with Marseille
Batshuayi signed a five-year contract with Marseille in summer 2014 and had to be patient as he was eased into life in Ligue 1. He made six starts and 20 substitute appearances in his first season with the club, finishing with nine league goals.
The nine-time French champions went through a turbulent time in his second year there but Batshuayi was one of the few bright spots. He netted 17 goals in 36 league matches and also scored four times in the Europa League. The pacy attacker finished the year with a goal against Paris Saint-Germain in the Coupe de France final but Marseille went down to a 4-2 defeat.
3) Chances at Chelsea
Batshuayi made a big-money move to Chelsea in the summer of 2016 and took just two games to notch his first Premier League goal. He netted five times in the league – despite only starting one game – in his first season in London and got four more in cup competitions. The highlight was when he came off the bench to score at West Brom in May 2017 – a goal that gave the Blues the win they needed to become Premier League champions.
“This is the beauty of football. A player that didn’t play a lot. Everyone thought he doesn’t count too much and then he scores the winning goal for the championship,” Chelsea teammate Cesc Fabregas said of Batshuayi on Sky Sports. “I mean, football is f------ unbelievable!”
This season Batshuayi bagged his first hat-trick for Chelsea in a League Cup game against Nottingham Forest in September 2017 and he got his second UEFA Champions League goal that month with an injury-time winner in a group match against Atletico Madrid. He had scored 10 goals in all competitions in the 2017/18 campaign before joining Dortmund.
4) Belgium over Congo
Given his parents’ origins, Batshuayi could have played for the Democratic Republic of Congo at international level. Having already represented Belgium’s Under-21 side, however, he released a statement in March 2015 confirming he wanted to play for the Red Devils. A week later he received his first call-up at senior level, and he scored on his debut against Cyprus later that month.
Batshuayi was named in Belgium’s Euro 2016 squad on the same day he became a father for the first time. His year then got even better when he scored with his first touch moments after coming on in Belgium’s 4-0 win over Hungary in the last 16 of the European Championship.
5) A fan of comics and cartoons
In a world where footballers are wary of standing out from the crowd, Batshuayi is something of an exception. The 24-year-old has caught the eye in the past by wandering around stadiums with a SpongeBob SquarePants bag on his back and has admitted that he sometimes watches cartoons – including his favourite – if he has trouble sleeping at night.
He also goes by the nickname “Batsman” – a nod to the comic book star Batman but also the Belgian's habit of appearing out of the darkness of the dug-out and striking as a substitute. Aubameyang is also a big fan of the Caped Crusader, famously donning a Batman mask alongside Marco Reus as the pair celebrated a derby goal against Schalke in 2015. Will Batshuayi be Reus' new Batman? To paraphrase Commissioner James Gordon: He's the hero Dortmund needs.