Vliesmähnen-Löwe

{3}{G}{W}: Monstrum 1. (Falls diese Kreatur nicht monströs ist, lege eine +1/+1-Marke auf sie und sie wird monströs.)
Solange der Vliesmähnen-Löwe monströs ist, hat er Fluchsicherheit und Unzerstörbarkeit.

León melena de lana

{3}{G}{W}: Monstruosidad 1. (Si esta criatura no es monstruosa, pon un contador +1/+1 sobre ella y se convierte en monstruosa.)
Mientras el León melena de lana sea monstruoso, tiene las habilidades de antimaleficio e indestructible.

Lion à crinière bouclée

{3}{G}{W} : Monstruosité 1. (Si cette créature n'est pas monstrueuse, mettez un marqueur +1/+1 sur elle et elle devient monstrueuse.)
Tant que le Lion à crinière bouclée est monstrueux, il a la défense talismanique et l'indestructible.

Leone Vellocriniera

{3}{G}{W}: Mostruosità 1. (Se questa creatura non è mostruosa, metti un segnalino +1/+1 su di essa e diventa mostruosa.)
Fintanto che il Leone Vellocriniera è mostruoso, ha anti-malocchio e indistruttibile.

羊毛鬣のライオン

{3}{G}{W}：怪物化１を行う。（このクリーチャーが怪物的でない場合、これの上に＋１/＋１カウンターを１個置く。これは怪物的になる。）
羊毛鬣のライオンが怪物的であるかぎり、これは呪禁と破壊不能を持つ。

양털갈기 사자

{3}{G}{W}: 괴수화 1. (이 생물이 괴수화하지 않았다면, 이 생물에 +1/+1 카운터 한 개를 올려놓는다. 이 생물은 괴수화한다.)
양털갈기 사자가 괴수화했다면, 양털갈기 사자는 방호 능력과 무적 능력을 갖는다.

Leão da Juba Lanosa

{3}{G}{W}: Monstruosidade 1. (Se esta criatura não for monstruosa, coloque um marcador +1/+1 nela e ela se tornará monstruosa.)
Enquanto Leão da Juba Lanosa for monstruoso, ele terá resistência a magia e será indestrutível.

Руногривый Лев

{3}{G}{W}: Чудовищность 1. (Если это существо не является чудовищным, положите на него один жетон +1/+1, и оно становится чудовищным.)
Пока Руногривый Лев является чудовищным, он имеет Порчеустойчивость и Неразрушимость.

绒毛狮

{3}{G}{W}：蛮化1。（如果此生物未蛮化，则在其上放置一个+1/+1指示物且它蛮化。）
只要绒毛狮已蛮化，它便具有辟邪与不灭异能。

絨毛獅

{3}{G}{W}：蠻化1。（如果此生物未蠻化，則在其上放置一個+1/+1指示物且它蠻化。）
只要絨毛獅已蠻化，它便具有辟邪與不滅異能。

Fleecemane Lion

{3}{G}{W}: Monstrosity 1. (If this creature isn't monstrous, put a +1/+1 counter on it and it becomes monstrous.)
As long as this creature is monstrous, it has hexproof and indestructible.

Pioneer Masters

Forgotten Realms Commander

{3}{G}{W}: Monstrosity 1. (If this creature isn't monstrous, put a +1/+1 counter on it and it becomes monstrous.)
As long as Fleecemane Lion is monstrous, it has hexproof and indestructible.

Commander 2017

Theros

An ability that triggers when a creature becomes monstrous won't trigger if that creature isn't on the battlefield when its monstrosity ability resolves.

Monstrous isn't an ability that a creature has. It's just something true about that creature. If the creature stops being a creature or loses its abilities, it will continue to be monstrous.

Once a creature becomes monstrous, it can't become monstrous again. If the creature is already monstrous when the monstrosity ability resolves, nothing happens.