Peekmorph
(You may cast this as a facedown 2/2 creature for
. You may activate abilities while its facedown, if you do, reveal this, and then shuffle your facedown creatures afterward.)

: Retractable claw lizard gets +2/+0 and trample until end of turn.
See Challenge # 134.
Playing up the "unknown" aspect of morph.
I like this. Unfortuantely, it's rather impractical if morphers are tapped, have auras on them, etc.