Operation Thunderball spanned 109 countries and resulted in more than 1,800 seizures of primates, big cats, reptiles and other creatures.
He will succeed China’s Meng Hongwei, who disappeared in September and later resigned after Chinese authorities said he was being investigated for suspected bribery.
Meng Hongwei's wife says she received a threatening phone call from a man speaking Chinese one week after her husband went missing.
Meng Hongwei is the latest high-ranking official to fall victim to a sweeping crackdown by the ruling Communist Party on perceived disloyalty.
Meng Hongwei stepped down as head of the international police agency days after his wife reported him missing.
Meng Hongwei hasn't been seen since he traveled to China late last month, his wife told police.
Browder tweeted about the saga in Madrid.