Based on Mirroria for Challenge # 100.

I toyed with ideas that seemed appropriate to Mirroria but didn't already exist. Especially cards which are simple enough for common. I decided if you have DFC already, this is an obvious compromise between "destroy on ETB" and "destroy on sac".

You'd have to decide whether to do the "same name and stats on the back" trick. Currently it's not allowed in the comp rules, I think? But I think it could be altered so it was OK. Else, you could tweak the name, and possibly give the creature bigger stats after it eats something -- that would be better flavour, but might be too much to think about for common.

Reminds me of Wickerbough Elder, which managed "bigger stats after it eats something" in a way appropriate to its set's mechanic (-1/-1 counters). This is a natural DFC equivalent. Good find.

I think this would be more interesting if its size were dramatically different. You could take it either way (gets larger or gets smaller), but doing "one-use" effects with no other change in size feels like it's... not taking full advantage of DFC, somehow.

OTOH, in Mirroria you absolutely want some commons that aren't going to be changing size, so this design is probably better for the set it's created for.

Thank you. Yeah, that's about what I thought. There were lots of good ideas with creatures which can level up or level down by transforming (for a cost, when it's dealt damage, when it activates an ability, etc).

But I thought in some ways, the art of double faced cards is leaving things out -- double faced cards can duplicate almost any other effect in the game, so you have to choose which specific aspect you're concentrating on at once. There had to be some creatures which didn't complicate combat maths, so I started with one of those :)

In fact, in a funny way, this needs DFC more -- monstrosity shows you can quite well indicate a phase shift with "put some +1/+1 or -1/-1 counters on this, if so, it has blah". The one thing you can't represent without DFC is staying the same size :)

Well, there's the Icatian Javelineers approach. But I guess that's not common-suitable these days because of "no counters on creatures except +1/+1 counters".