Ability: When Aether Poisoner enters the battlefield you get {E}{E}.
Does this mean if I already have one aether poisoner on the field and I play a second that the ability will stack and I'll get {E}{E}{E}{E}?
If the answer to the previous question in yes, then consider the following:
{U}: Dukhara Peafowl gains flying until end of turn.
Does this mean that if I have 2 Dukhara peafowls I merely have to pay {U} once in order to give both flying?