Unchoosable

Unchoosable is a slang term the state given to creatures that can't be chosen by abilities. However, they can still be attacked and blocked as normal.

Details
This ability is featured in many variants, but is most commonly found in the Light Civilization.

An unchooseable creature cant be selected as a target of an opponents ability. As most forms of commonly used removal requires a single target to be chosen (eg. Terror Pit, Aqua Surfer, Father Earth), untouchable creatures can easily make the removal cards useless.

呪文の効果であれ、クリーチャーの能力であれ、テキストに「クリーチャーを1体選び」などと書かれている場合でも選択できない. また、「クリーチャーを1体破壊する」などの間接的に選択を伴うテキストであれば、やはりアンタッチャブルのクリーチャーを選ぶことはできない. バトルゾーンのクリーチャーがそれ1体しかいなくても、それがアンタッチャブルならばもちろん選ぶことはできない.

However, they can still be affected by removal cards that don't choose a specific target that either affect one or both sides of the battle zone at once (eg. Super Spark, Apocalypse Day, Funk, Guard of Hope). They are also vulnerable to cards your opponent may play that cause you to choose the creatures (eg. Necrodragon Abayo Shabayo, Olzekia, General of Decapitation), bypassing the ability completely.

Due to the strength of this ability protecting them from most removal, many creatures with the ability have lower power and can be dealt with cards that allow them to attack untapped creatures.

Trivia

 * It is likely based off of the Magic: The Gathering keyword ability of Hexproof which reads (This permanent can't be the target of spells or abilities your opponents control.)