Chimney Goyf

• WWizards of the Coast2019-11-12
  Official Ruling
  The ability that defines Chimney Goyf’s power and toughness works in all zones, not just the battlefield. If Chimney Goyf is in your graveyard, it will count itself.
• WWizards of the Coast2019-11-12
  Official Ruling
  The card types that can normally appear on cards in a graveyard are artifact, creature, enchantment, instant, land, planeswalker, sorcery, and tribal. Legendary, basic, and snow are supertypes, not card types.
• WWizards of the Coast2019-11-12
  Official Ruling
  If an instant or sorcery spell deals damage to Chimney Goyf or lowers its toughness, that spell is put into its owner’s graveyard before state-based actions are performed. If that spell is the first of its type to enter a graveyard, it will raise Chimney Goyf’s toughness before the game checks to see if Chimney Goyf dies.
• WWizards of the Coast2019-11-12
  Official Ruling
  Some playtest cards have unusual type lines. To determine whether those cards have a card type not listed above, refer to that card’s Card-Specific Notes in this document.
• WWizards of the Coast2019-11-12
  Official Ruling
  Chimney Goyf counts card types, not cards. If the only card in all graveyards is a single artifact creature, Chimney Goyf will be 2/3. If the only cards in all graveyards are ten artifact creatures, Chimney Goyf will still be 2/3.

Rulings via Scryfall