Phyrexian Doppelganger Question

[KingHeavy]

Hi, I was trying to put a creative control deck together that used Renegade Doppelganger to copy a freshly played Putrefax, resulting in 10 hastey poison counters.  Then, looking for more threats to copy with the 'ganger I remembered Phyrexian Dreadnaught.  Now, since the doppelganger would already be in play, could I cast a Dreadnaught, copy it, let the original die and then attack with the 'ganger being a 12/12 trampler that doesnt have summoning sickness?

If you have an answer to this question, please reply or PM me as I dont check this account all that often.

Thanks for the help!

[Delha]

Yes, your Dreadnaught idea works.

For more ideas in that vein, I recommend you look up the deck "Full English Breakfast". Just bear in mind that the deck was built at a time when combat damage went on the stack, so tricks involving that mechanic no longer work the same.