Dolls or Demons??

Mystery unfolds
NOTE: NAME OF REAL CHARACTERS NOT USED.

Tommy (15 years) became dumb ( not able to speak) after the death of his sister Annie (9 years). People concluded that it must be as a result of shock from his sister's death, whose dead body was found dumped in the sewer. Nobody knew the real cause of her death until Tommy's lost diary was found years later and it read;
" Annie had a large doll, the size of a toddler. She was very fond of the doll that when at age 9 she said she didn't want a doll again it was surprising. Annie dumped the doll in the backyard but whenever she woke she found the doll in her bed and she concluded I was probably the one who put it there but when she confronted me about it I denied and we asked my parents but they denied it also. My mom decided to throw the doll in a pit outside the compound. Since then my sister has been scared of going to the toilet alone and I never knew why. Once she begged me to follow her to the toilet but I refused sarcastically, I became remorse when she began to cry. I decided to follow her and she begged me to watch her but since she was a girl I decided not to face her but back her. She was through when she began to wash her Hands and I turned to face her and then I saw it. A long hand came from the toilet and it dragged Annie into the toilet. I screamed and tried dragging her feet but it was slippery. I decided to drag the hand dragging Annie and after much effort I was able to drag it out but I lost Annie. The hand was plastic and I immediately knew it belonged to her doll. I ran in tears to the pit where mom threw the doll but it wasn't there. But a small hole was in the pit. The hole which was enough to size a toddler. And the after much investigations it was discovered the hole led to the sewer.