Koma-inu(Korean dog) 狛犬

A pair of stone guard dog=Koma-inu stand outside the gates
of Japansese Shinto shrines .
Right side of Koma-inu depicted with their mouth open
(to scare off demons)
Left side of Koma-inu closed (to shelter and keep in the good spirits).

Another traditional explanation for the open/closed mouth relates
to Ah and Un ("Ah＝阿" is the first letter in the Sanskrit syllabary
and symbolizes open mouth, while "Un＝吽" is the last letter and it
represents a closed mouth.)
The combination is said to symbolically represent birth and death.
Photo is Koma-inu stone guard dog in front of Kikko shrine(Iwakuni).