After talking to my peers I realised how much I wanted to see Megan's Alien in 3D and still get to show it in the final animation. Of course I want to maintain the 2D part because it adds charm to it and it definitely looks like a child's depiction this way. Or I could have both: the child depicting the alien in a 2D way and the 3D Alien coming to life afterwards.
I decided to test it out, so I modelled him using basic shapes. I really don't know if I should go for it or not. It will mean more work for me but it will certainly enhance my skills in animation if I do include him.