Moll

Shapeshifting parasitic aliens designed to secretly integrate into society and steadily take over the population are usually pretty bad. Especially when they have a digestive tract so powerful it can digest metal, and then use said metal to turn its body into a living weapon.

Yes, most shapeshifting parasitic aliens are pretty bad, and then there's Moll. Moll is one of these aliens, except she's a little messed up in the head. When Moll's craft was launched toward Earth it should have been an easy task to conquer the little unsuspecting planet, the alien shapeshifter was more than prepared, unfortunately her craft wound up crash landing and she got a pretty good smack to the head that wound up leaving her an amnesiac with fragmented memories.

Moll's natural form is what you see here, a tall lanky creature roughly 9 feet tall, not counting ears or tail. She's incredibly mobile, designed to move easily throughout her surroundings, being tall enough to hide and traverse through treetops and other difficult terrain, this form is also fairly conspicuous though, that's where being a shapeshifter comes in. Moll is able to perfectly recreate the shape of other creatures, the problem is when she does this, her fragmented memory may cause issues and wind up leaving her a blank slate. Every time she changes her shape she risks starting anew. The bigger the change, the bigger the risk.

Occasionally she may luck out and everything will connect just right allowing Moll to remember her primary mission as well as all the other events she has experienced. When these rare moments of clarity occur she is a considerable force to be reckoned with and her plans for world domination can be quite intense. Luckily though it doesn't take much more than a comedically timed bonk to the head to get her back to a more pleasant and friendly blank slate not trying to enslave the world.

Most people who have met Moll will never know the full extent of her story though because most of the time, even she doesn't.

One convenient outcome of her crash landing though is that the fragmentation of her mind has allowed her to live an incredibly long life. Her exact age is unknown. Her species when sent to an alien world to begin the conquest is pre-programmed with a self destruct sequence. Being such a dangerously versatile living weapon they're set to expire after a pre-set period of time. Because of Moll's accident this aspect has failed, and with her highly malleable shape shifting body, as long as she maintains herself she has the potential to live indefinitely. Though again, most people will never know that Moll is an extremely old alien parasite out to conquer their world and enslave them, because each shift has the potential to start her anew leaving Moll, and those around her to believe she's nothing more than the current form she has taken.