Walcott was speaking after Arsenal achieved the home and away winning double in their Champions League quarterfinal against Real Madrid.
He told BBC Sport: "Mikel Arteta has built this Arsenal team from his mind and his connections with each individual talent in that team, and he's built them to be one mind.
"When I say one mind, I mean he's so serious and some people say he's too serious, but everyone's on the same path as him. And that's why I think their aura is him.
"That's the difference about Arsenal, they don't have the players with the big egos. They're a team and I think Arteta takes it away from the team. I think its a good thing."
Walcott also had a word for Bukayo Saka, who shone despite having a 13th minute penalty saved by Real goalkeeper Thibaut Courtois.
He added: "He typified it from start to finish because he had a night where it could've gone the other way for him but, for me, he is such a resilient character in that dressing room."