Thereafter, because of being pulled into the water and fighting for many long years, the elephant became diminished in his mental, physical and sensual strength. The crocodile, on the contrary, being an animal of the water, increased in enthusiasm, physical strength and sensual power.
Srimad Bhagavata Purana
श्रीमद्भागवतमहापुराणम्
मूल श्लोकः
ततो गजेन्द्रस्य मनोबलौजसां कालेन दीर्घेण महानभूद्व्ययः । विकृष्यमाणस्य जलेऽवसीदतो विपर्ययोऽभूत्सकलं जलौकसः
tato gajendrasya manobalaujasāṃ kālena dīrgheṇa mahānabhūdvyayaḥ | vikṛṣyamāṇasya jale'vasīdato viparyayo'bhūtsakalaṃ jalaukasaḥ
SB 8.2.30