Check out the FAQ Entry 3.25 found on page 11 of the FAQ.
(3.25) Card Type Changes to Character
Any time a non-character card type becomes or counts as a character, it loses all other card types it might possess while it is a character. If for any reason, a non-character card that is functioning as a character is killed, said card is placed in the discard pile instead. Effects that trigger from said card being killed may still apply.
Similarly, if a non-character card type becomes a character and claims power, that power counts towards your victory total. If at any time said card is no longer a character, the power that it has claimed thus far is not discarded, but it no longer counts
towards your victory total. If said card once again becomes a character, any power it has claimed will again count towards its controller's victory total.
So a card is only one type of card, that is whatever type it currently is, basically.
As for Milk of the Poppy, the attachment doesn't leave the character until Step 6, the same time the character itself leaves play, so yes - Milk still blanks a character - even if they are moribund.