Quarter each apple and remove the core, cutting a shallow wedge from the skin side of each quarter to form the upper and lower 'lips' of the mouth.
Dip each cut apple piece briefly in the lemon water, then pat dry.
Spread about half a teaspoon of sunflower seed butter along the inner flesh of the lower lip piece.
Press 4 sunflower seeds into the seed butter along the lower lip to form teeth.
Place one strawberry half, cut side down, in the centre of the lower lip as the tongue.
Rest the upper lip piece on top at a slight angle so the mouth looks open and menacing.
Arrange on a platter and serve within 1 hour for best colour.