Goosebumps 2 is officially called Slappy Halloween, according to author R.L. Stine who also revealed that the movie has started filming.
It should be noted that there was also a viral Goosebumps card that went out during the original movie’s release that contained the title Slappy Halloween.
Slappy the Dummy is making his return for Goosebumps 2, but it’s still not clear if Jack Black will return to voice the character at this time.