Avalan's Failed Experiment

Hexproof
At the beginning of your upkeep, choose a
non-Legendary creature you control not named
Avalan's Failed Experiment. This card becomes
a copy of the chosen creature, except it gains this ability.
"One moment, it's an ooze, and then when you blink,
it's become a clone of you. It seems to be able to
transform into anything!"