Its a really powerful and really popular Temur commander, and you can tweak it based on your meta and personal play style
Because the spell is an Aura spell, its controller must choose a legal target for that spell as defined by its enchant creature ability and rule 601.2c
If youre in Blue in this set, you definitely need to draft a few copies of Mesmerizing Dose to deal with your opponents threats
Take a look: Weirdly, this particular rambling McNally has never seen a reprint, so any copy out there that you might see is forever just Creature Construct. As per official rulings, it is indeed an artifact, if you couldnt tell by the frame, the colorless casting cost or the general animated map-ness of it all
Special Summon it, ignoring its Summoning conditions
Chameleon, Master of Disguise was first released in the set Marvel's Spider-Man, illustrated by Javier Charro