Elder Land Wurm — ruling 1

Another effect can give Elder Land Wurm defender after it has lost it. Blocking again will cause it to lose that instance of defender too.

Elder Land Wurm : règles, fonctionnement et interactions (MTG)

Elder Land Wurm is one of those cards players keep asking about. Here is, in plain words, what its official text says, the rulings published by Wizards of the Coast, and the combos players actually run.

Official card text

Defender, trample When this creature blocks, it loses defender.

How it works : Elder Land Wurm

Original English text — Wizards of the Coast / Scryfall

#1October 4, 2004· Wizards of the Coast
Another effect can give Elder Land Wurm defender after it has lost it. Blocking again will cause it to lose that instance of defender too.
No other card is named in this ruling.