No. हाथी is a male noun and as such would remain हाथी when pluralised.
You will sometimes see the plural form written as हाथियाँ. This type of construction is only used for female nouns (eg: बिल्ली - बिल्लियाँ) so हाथियाँ is technically incorrect.
In the oblique(possessive) case, you use हाथियों but this has to be followed by a postposition like के, से, में etc. (Eg: हाथियों के पैर बड़े होते हैं )