Verses with the word mouths in the New Testament (5 verses):

Titus 1:11
Whose mouths must be stopped, who subvert whole houses, teaching things which they ought not, for filthy lucre's sake.

Hebrews 11:33
Who through faith subdued kingdoms, wrought righteousness, obtained promises, stopped the mouths of lions.

James 3:3
Behold, we put bits in the horses' mouths, that they may obey us; and we turn about their whole body.

Revelation 9:17
And thus I saw the horses in the vision, and them that sat on them, having breastplates of fire, and of jacinth, and brimstone: and the heads of the horses were as the heads of lions; and out of their mouths issued fire and smoke and brimstone.

Revelation 9:18
By these three was the third part of men killed, by the fire, and by the smoke, and by the brimstone, which issued out of their mouths.