Skarrg Guildmage — ruling 1

Only creatures you control when the first ability resolves will gain trample. Creatures that come under your control later in the turn won’t have trample. Lands you control that aren’t creatures also won’t gain trample, even if you use the second ability to turn them into creatures later in the turn.

Skarrg Guildmage — ruling 2

Skarrg Guildmage’s second ability doesn’t affect the land’s name or any other types, subtypes, or supertypes (such as basic or legendary) the land may have. The land will also keep any abilities it had.

Skarrg Guildmage : règles, fonctionnement et interactions (MTG)

Skarrg Guildmage 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

: Creatures you control gain trample until end of turn. : Target land you control becomes a 4/4 Elemental creature until end of turn. It's still a land.

How it works : Skarrg Guildmage

Original English text — Wizards of the Coast / Scryfall

#1January 24, 2013· Wizards of the Coast
Only creatures you control when the first ability resolves will gain trample. Creatures that come under your control later in the turn won’t have trample. Lands you control that aren’t creatures also won’t gain trample, even if you use the second ability to turn them into creatures later in the turn.
No other card is named in this ruling.
#2January 24, 2013· Wizards of the Coast
Skarrg Guildmage’s second ability doesn’t affect the land’s name or any other types, subtypes, or supertypes (such as basic or legendary) the land may have. The land will also keep any abilities it had.
No other card is named in this ruling.