Need help with making up an extraterrestrial

cuz see i have this project and the goal is to design an alien from another planet to describe how each alien evolved according to each theory. (lamark and darwins theory). what i was thinking of doing is starting off this creature being non-intelligent to adapting into intelligence to survive in the environment they r in. and they adapt to it and all the unintelligent ones die off and i have to have examples for each theory on how and why that happens. what is a living creature outside of earth that has no intelligence called, whats the term? and i know that this isnt possible (for an unintelligent being to turn intelligent) but my teacher said that didnt matter we just have to make it up and be creative.referring to my project, what would happen to something unintelligent for it to not survive? kinda like if u look at it like if humans had no intelligence, what would happen to us? how would they exactly die off? and what can i make up, for the creature to turn unintelligent to intelligent? example, giraffes once had short necks and there necks grew because of them stretching up at trees for food and the ones with the long necks survive and pass it on to future generations and the short necks die and extinct. so how could i make up something to turn an unintelligent being from intelligent? it could be made up and fictional, i just dont know where to start. idk if u know what i mean and get what im saying. I hope u guys understand this lol. Thanks to everyone who answers!

BQ: what is the difference between an extra dimensional being and an extraterrestrial?

Well, a creature that isn't "intelligent" is anything besides a human... and a non intelligent creature would die off from intelligent creature. Think of how us humans steal "unintelligent" creatures lands in the rainforest and they die. That is how. That is a good example if an advanced alien race ever found us, they would steal our planet and resources and kill us all. Start your alien off similar to the intelligent one, but without the "intelligent" traits. BTW: a intelligent creature is intelligent if it can create tools to achieve a purpose. FYI: monkey can unpeel banana...