At the beginning of your upkeep, put a +1/+1 counter on this creature.
This creature can't attack or block unless you pay for each +1/+1 counter on it.
Illustrated by Dave Dorman · Mirrodin · #214
There are no rulings for Myr Prototype.
This creature enters with three +1/+1 counters on it.
At the beginning of your upkeep, sacrifice this creature unless you remove a +1/+1 counter from it.
, Discard a card: Put a +1/+1 counter on this creature.
Whenever this creature attacks or blocks, put a -1/-1 counter on it at end of combat.
Fear (This creature can't be blocked except by artifact creatures and/or black creatures.)
At the beginning of your upkeep, you may move a +1/+1 counter from target creature onto this creature.
Modular 3 (This creature enters with three +1/+1 counters on it. When it dies, you may put its +1/+1 counters on target artifact creature.)
This creature doesn't untap during your untap step.
At the beginning of your upkeep, you may pay . If you do, untap this creature.
Flying
This creature enters with four +1/+0 counters on it.
At end of combat, if this creature attacked or blocked this combat, remove a +1/+0 counter from it.
, : Put up to X +1/+0 counters on this creature. This ability can't cause the total number of +1/+0 counters on this creature to be greater than four. Activate only during your upkeep.