Weak or damaged front leg joints. The front legs of many toys are connected by joints that allow them to move. These joints can be made of either plastic or metal. If the joints are made of plastic, they can break or become stripped, making them unable to properly support the toy's weight. If the joints are made of metal, they can become loose over time, also causing the toy's front legs to collapse.
Damage to the toy's body. If the toy's body is damaged, such as if it has a hole or crack in it, this can cause the front legs to become misaligned and unable to support the toy's weight.
The toy is too heavy for its front legs. If the toy is too heavy for its front legs, this can put too much stress on the legs and cause them to collapse.
Misassembled toy. If the toy is not properly assembled, the front legs may be assembled incorrectly, causing the toy to fall on its nose.