Yes, Mutavault has summoning sickness when it becomes a creature.
When a land becomes a creature and dies in a game, it is put into the graveyard as a land card, not a creature card.
He welcomes him at first but then becomes frightened
She dies in Fading Echoes from sickness Mistyfoot becomes Mistystar and Reedwhisker is deputy
Once a creature is blinded it becomes easy prey.
sea horses!
The Daboia (or Russell viper) is primarily a nocturnal creature. However, when the weather becomes cool, it becomes active in the daytime.
In game terms, a 'creature' or 'creature permanent' is something on the battlefield. While in your hand, it is only a 'Creature Card', and while on the stack, a 'Creature Spell'. It only becomes a creature when it resolves to the field. Because of that, when a card requires you to sacrifice a 'creature', it can only ever be referring to something you have on the battlefield.
After the animal leaves, the shelter becomes home to another creature.
he becomes excitable and act irrationally
I believe that if people would like to exercise than nobody should stop them. When it becomes a health issue to the point of sickness or death I believe that someone might need to step in and tell them the possibly of sickness.
When you tap a target creature in Magic: The Gathering, it becomes exhausted and cannot attack or use its abilities until it untaps during the next untap step.
The "Song of the Dryads" card in Magic: The Gathering turns a creature into a Forest land. The enchanted creature loses all abilities and becomes a basic Forest with no abilities.