Hawzah News Agency – Imam Baqir peace be upon him says:

مَثَلُ الحَريصِ على‏ الدُّنيا مَثَلُ دُودَةِ القَزِّ: كُلَّما ازْدادَتْ مِن القَزِّ على‏ نَفْسِها لَفّاً كانَ أبْعَدَ لَها مِن الخُروجِ، حتّى‏ تَموتَ غَمّاً.

'The similitude of the one who covets this world is as the caterpillar: the more silk it spins around itself, the harder it makes its exit for itself, until it dies of grief.'

Source: al-Kafi, v. 2, p. 316, no. 7