Undergrowth — When this creature enters, target creature gains vigilance and gets +X/+X until end of turn, where X is the number of creature cards in your graveyard.
This creature can't be blocked by more than one creature.
(05/10/2018)
If Vigorspore Wurm gains menace, it can't be blocked at all.
(05/10/2018)
Creature cards with other types, such as artifact creature cards, count for undergrowth abilities.
(05/10/2018)
Because tokens aren't cards, they never count for undergrowth abilities.
(05/10/2018)
The value of X is determined only as the undergrowth ability resolves. If the number of creature cards in your graveyard changes later in the turn, the target creature is unaffected.
(05/10/2018)
If there are no creature cards in your graveyard, the target creature just gains vigilance until end of turn.
