Intimidate

Intimidate is a deprecated keyword ability. A creature with intimidate can't be blocked except by artifact creatures and/or creatures that share a color with it.

Description
Intimidate was introduced with the Magic Comprehensive Rules revision for Magic 2010 even though no cards with that keyword were printed in that set. It functions similar to Fear, which was considered to have the wrong flavor and could only be used in black. Intimidate replaced Fear as an evergreen mechanic among new and reprinted cards. It first appeared in Zendikar. Its last appearance was in Magic 2015. Khans of Tarkir block had no cards with intimidate. As of Magic Origins, intimidate is no longer an evergreen mechanic, having been replaced with menace.

Because it has too high a variance, R&D doesn't expect Intimidate to be used anymore. While there is counterplay in some respects (picking up artifact creatures), the strength of the creature is determined when the decks are paired. As color changing is no longer a common mechanic, there is no architecture to allow for players to prepare for it, unlike for Flying. Mark Rosewater rates the mechanic a 10 on the Storm Scale.

Rulings

 * Intimidate looks at the current colors of a creature that has it (hence why it was not applied retroactively to cards like Skirk Shaman). Normally, Bladetusk Boar can't be blocked except by artifact creatures and/or red creatures. If it's turned blue, then it can't be blocked except by artifact creatures and/or blue creatures.
 * If an attacking creature has intimidate, what colors it is matters only as the defending player declares blockers. Once it's blocked, changing its colors won't change that.
 * Artifact creatures can block creatures with intimidate no matter what colors either of them are.
 * A multicolored creature with intimidate can be blocked by any creature that shares a color with it, in addition to artifact creatures. For example, a white-blue creature with intimidate can be blocked by white creatures and/or blue creatures, no matter what other colors they are.
 * A colorless creature with intimidate can be blocked only by artifact creatures. It can't be blocked by colorless nonartifact creatures. In fact, a colorless nonartifact creature can't block a creature with intimidate at all.

Enchantments that grant Intimidate to a creature

 * Cavern Lampad
 * Grisly Transformation
 * Gruesome Deformity
 * Predator's Gambit
 * Vow of Malice

Artifacts that grant Intimidate to a creature

 * Nim Deathmantle
 * Executioner's Hood</c>