Guenhwyvar 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

Trample

How it works : Guenhwyvar

Original English text — Wizards of the Coast / Scryfall

No additional ruling has been published for this card.

Interactions with other cards

These cards' text mentions Guenhwyvar.

Drizzt Do'Urden

Double strike When Drizzt enters, create Guenhwyvar, a legendary 4/1 green Cat creature token with trample. Whenever a creature dies, if it had power greater than Drizzt's power, put a number of +1/+1 counters on Drizzt equal to the difference.