"I'm not going to lie, I'm a massive Celtic fan, so I love him! My whole family loves him," Gray said in his first interview with Tottenham's media channels.
"He's a massive factor. Playing under a really good manager is really important for me. I've got loads to learn because I'm only 18. It's obviously a massive club and an opportunity I couldn't turn down. I'm really excited to play and get started with the team. It still hasn't sunk in, to be honest, and I don't think it will for the next few days until we've played a few games and I've got to meet everyone."
He also revealed that the allure of European football also led him to choose Tottenham instead of Brentford, with whom he had already agreed personal terms.
"When Spurs came and I had the opportunity to play in the Champions League eventually, and Europa League this year, I couldn't really say no," he added.
"I know so many players that are here - not so much the first team but the young lads - and obviously it's a massive project under Ange. It's something I want to be part of."