CHĀNDOGYA UPANISHAD · 6.9.3
त इह व्यघ्रो वा सिंहो वा वृको वा वराहो वा कीटो वा पतङ्गो वा दंशो वा मशको वा यद् यद् भवन्ति तद् आभवन्ति ॥
ta iha vyaghro vā siṃho vā vṛko vā varāho vā kīṭo vā pataṅgo vā daṃśo vā maśako vā yad yad bhavanti tad ābhavanti ॥
'Whatever these creatures are here, whether a lion, or a wolf, or a boar, or a worm, or a midge, or a gnat, or a musquito, that they become again and again.
F. Max Müller · The Upanishads, Sacred Books of the East 1 (1879)