Dr. Price, the snake expert found by the FBI. He doesn't go Spock Speak, he doesn't lord his knowledge over them, he doesn't marvel at the snake's odd behavior, and he is very fast and rational because he knows people's lives are in danger here. As noted on the main page, this is what movie scientists should be.
Also when they find the guy who gave Eddie Kim the snakes and the man is bitten by one that escapes in a scuffle, Price cheerfully tells him the species and it's lethality and withholds the anti-venom until the man agrees to cooperate with the FBI. He's how they got the evidence against Kim.
Tony, the martial artist passenger, he kills crazed poisonous snakes with his bare hands.