New Mandy was a living toy that Billy built from various toys that he gathered from his room. She had a Mr. Gourd Head for body and eyes, a toy T-Rex's arms, train engine wheels for legs, and a bat for hair. She only appeared in Tickle Me Mandy.
The New Mandy is created when Billy becomes lonely after Mandy goes on vacation so Grim suggests that he make a replacement Mandy until she comes back. They make her from the items mentioned above after Billy points out that she has no mouth Grim draws on he initially draws a smiling mouth, until Billy points out that Mandy never smiles.
Grim uses his powers to bring her to life. When Billy mentions that it doesn't work he notices a switch and activates it bringing her to life. The first thing she does is scream then asks Billy if he wants to play, which he happily obliges. Things are going great until she steals his very expensive crayons as he calls them she breaks all but one and uses it to draw all over his living room until the crayon runs out she then throws a temper tantrum, Billy is now frightened of her and doesn't want anything to do with her, she follows him everywhere repeatedly asking him if he wants to play each time he responds with "NO!",
Later that night, Billy goes to bed and notices New Mandy in his room still asking to play. Billy screams and calls for Grim. Grim explains to him that she doesn't need to sleep, like he does, and that she will be waiting for him in the morning. Billy has a nightmare that New Mandy terrorizes him, multiplies herself, and beats him with a spatula. The next day the doll is waiting for him on the seesaw. He reluctantly goes off to play with her when he notices the real Mandy arriving back, and is overjoyed. Mandy spots the doll and asks who is she, the doll replies "Hi, I'm Mandy. Wanna play?"
Mandy explains that she is the only Mandy in this neighborhood and slams the other side of seesaw to the ground causing New Mandy to go flying into the sky, fall down to Earth and smash to pieces. Later that night they hold a funeral for the doll and Billy is in tears. Mandy asks him why he is crying if he didn't even like it. Billy says that he wants to be alone, he looks at the shoebox her remains are buried in and a clawed hand grabs his nose and shouts "PLAY! PLAY!"
- New Mandy, just like Mandy, was voiced by Grey DeLisle, but used a more childlike voice instead of sounding like the real Mandy.