Abstract: A doll with simulated physiological functions, in particular a toy doll in the form of a teddy bear, is described. The teddy bear has a head with eyes that can move and a mouth that opens and closes. A lower jaw pivots about a first axis to provide the opening and closing action of the mouth. A mechanical linkage means is provided to transmit a movement of the lower jaw to another part of the doll, for example to the eyes, whereby opening and/or closing of the mouth, for example when feeding the teddy bear, can produce a simulated physiological response from the doll, for example a responsive eye movement. The mechanical linkage means also actuates a sound generating means. The arrangement of the mechanical linkage means is such that there is a degree of unpredictability in the simulated physiological functions which enhances the long term play value of the doll and increases the enjoyment of a child. Incorporating other simulated physiological functions further enhances the play value of the teddy bear.