I think this is from Predator, even though the ammo jacket doesn't match what the character Mac Eliot (Bill Duke) wears in the film.

Some similarities between Predator and Tonari no Totoro:

• Have a scary titular monster
• Were released within less than a year of each other. Predator on June 12, 1987 and Tonari no Totoro on April 16, 1988.