Is the part time job as freelancer is legal for an expat ?

You would need to get immigration approval for the second employer

The ESD website explains the process under the Downloads section

https://esd.imi.gov.my/portal/downloads/

Best to maintain transparency and be paid into a bank account. The income from Y is taxable and you have to report it in your tax return

it means i can work for two employers but i need to declare the second employer as well. Am i correct ?
But i am unable to understand which form i need to fill to declare the second employer?

Did you check the link provided above under Second Location requirement? There is  a Checklist and DP11 form obtained via links.

Gravitas wrote:

Did you check the link provided above under Second Location requirement? There is  a Checklist and DP11 form obtained via links.

Yes. I checked it but unable to get inference whether second location implies to second employer.
Thanks for clearing out the confusion.
Thanks Gravitas.. Appreciate your prompt response..