Altered Ego

If the chosen creature is copying something else (for example, if the chosen creature is another Altered Ego), then your Altered Ego enters as whatever the chosen creature copied.

If you copy a double-faced creature, Altered Ego will be a copy of the face that's up when Altered Ego enters. Because Altered Ego is not a double-faced card, it won't be able to transform. If an effect instructs you to return it to the battlefield transformed when it leaves the battlefield, it won't return and will remain in its new zone.

Altered Ego copies exactly what was printed on the original creature (unless that creature is copying something else or is a token; see below). It doesn't copy whether that creature is tapped or untapped, whether it has any counters on it or any Auras and Equipment attached to it, or any non-copy effects that have changed its power, toughness, types, color, or so on.