It is not permissible to sell toys that have music, because of the proven report that it is haraam to listen to music.
See the answer to question no. 5000
And it is not permissible to sell games that include corrupt beliefs or the symbols of deviant sects.
Please see the answer to question no. 22069.
There is nothing wrong with selling dolls for children, even if they move or speak and the like, so long as they are free of music.
See the answer to question no. 119056.
It is not permissible to sell haraam toys or to help in that in any way whatsoever, such as administration, accounting, carrying or transporting, because that comes under the heading of cooperating in sin and transgression. Allah, may He be exalted, says (interpretation of the meaning):
“Help you one another in Al‑Birr and At‑Taqwa (virtue, righteousness and piety); but do not help one another in sin and transgression. And fear Allaah. Verily, Allaah is Severe in punishment”
If the toyshop includes both things that are permissible and things that are haraam, but it is possible for the employee to work in a department that has nothing to do with the haraam toys, it is permissible for him to work there. Otherwise he is sinning because of his participation in selling haraam things or helping others to do so.
It should be noted that there are many ways of earning a living, and if a person fears Allah, He will help him and guide him, and will grant him provision from sources he could never imagine, as He says (interpretation of the meaning):
“And whosoever fears Allaah and keeps his duty to Him, He will make a way for him to get out (from every difficulty).
3. And He will provide him from (sources) he never could imagine. And whosoever puts his trust in Allaah, then He will suffice him. Verily, Allaah will accomplish his purpose. Indeed Allaah has set a measure for all things”
And Allah knows best.