To become a "Creature-Robot Cross Breeder" the goal is to get to level 9 of the science career. Not too bad with the right traits. Fawn Snow (my chosen Sim) has the Ambitious, Angler, Green Thumb, Handy and Workaholic traits. The wish/career requires the Angler, Green Thumb and Handy skills to get a good performance rating. The Ambitious and Workaholic mean I can work at home, ask my boss for promotions with less fear of regection, and work hard with less stress. I play with static needs, which would make it seem easier but I'm not all work and no play. I only do what she wants according to her wishes (so if she wants to work great, if she wants to socialize great as well!)
Here is a Fawn - as a Creature-Robot Cross Breeder. (I'm going to change traits and outfits according to wishes!)
At the end it was on week 3, day 4 (25 days total) that Fawn received her lifetime wish. She is now level 9 in the science career and a "Creature-Robot Cross Breeder". This is a weird wish since it goes to level 9 and not level 10 of the career.
But I'm going to keep her working for one more day and get that promotion to put Fawn at Science career level 10. Next day was a day off for Fawn, so we had to wait an extra day to complete this. Week 3 day 6 (27 days total) Fawn reached level 10.
Next wish - Becoming a Master Thief!