I have received a couple inquiries about making an Ezio costume for children. While I don’t have a pre-made pattern (for children or adults), here are some (untested) suggestions for a couple commercial patterns and online tutorials that will help you with the basic shapes. Some pattern adjustments are required, but hopefully it isn’t too complicated.
First of all, some disclaimers:
1) I am not a parent and I have minimal interactions with children, so I don’t have a good sense for how big kids of any specific age are. I leave it to you (parents, grandparents, aunts, uncles, etc.) to choose the correct pattern sizes for the wanna-be Child Assassin in your life.
2) These pattern suggestions are for Ezio’s attire in AC2:Brotherhood and use medieval and renaissance costume templates. There is enough shape similarity that you could adapt these for other versions of Ezio and maybe Altair. If you want to make a Conner, Edward, or Arno costume, I recommend looking for pirate or colonial/American Revolutionary-era costume patterns.
3) Again, this post is for a child’s costume (probably younger than 12). If you want to build an Ezio costume for a teenager or adult, take a look at my previous posts about my husband’s Ezio costume: Part 1, Part 2, and Part 3. These can be adapted for women if you wish to cosplay a genderbent Ezio. I also wrote about my lady-assassin costume here.
Commercial Patterns
Thankfully there is no shortage of kid’s costume patterns – Simplicity, McCalls, and Butterick all offer many options. I recommend looking at costumes for knights, kings, musketeers, and renaissance-era characters. (Side note – I really hope people are out there sewing knight and musketeer costumes for little girls too!)
Materials
I recommend fabrics that can take a bit of a beating and can be easily washed. If you wish to add red lining for the cape and maybe the hood interior keep in mind that the red lining will make it hard to wash these fabrics together. I used an upholstery microsuede for the cape and doublet and a non-bleeding red polyester satin for the lining (think prom dress fabric). Ask your fabric store staff for fabric recommendations.
Hood
Even though this hood is inspired by the 3rd Assassin’s Creed game, I think it is a good tutorial and should work for Ezio as well. I like this tutorial because if the hood isn’t attached to the doublet, the child can grow and continue to wear this for other imaginative play.

Long tunic
Pattern suggestion – McCalls 5500. I like the look of the tabbard (the long tunic) of version A – the one that is pointed (upper right). BUT I also like the way versions B & C split apart to allow leg movement. This tunic pattern will need to be lengthened at the waist so that it reaches past the knee.

(My adult pattern was modified a little differently, but this gives you an idea of the shape you are aiming for.)
For the slightly puffy Renaissance sleeves, use the sleeves from version C (the green one). Add trim or a spiral decorative stitch to mimic the black trim detail on Ezio’s sleeves. I recommend adding this detail which the sleeve is flat, BEFORE you attach the sleeve to the body.
(You can can also just sew the puffy sleeves and the “tails” to the following doublet if you want to make fewer costume pieces.)
Doublet
If you are comfortable with drafting patterns (or even if you aren’t, challenge yourself!), this online tutorial makes drafting a kid’s version of Ezio’s doublet look very doable. It is based on the shape of one of the kid’s t-shirts. You can simplify the lines of Ezio’s doublet, and just create the boy’s version of the doublet in white and I think it would work for Ezio.

If you would prefer to modify a commercial pattern, try Simplicity 5520, view D.
Caplet
Pattern suggestion: Simplicity 1583. Use this pattern (View D) and make only half of the cape (the left arm side). You can hold it in place with some brown faux leather straps. This pattern is a little kid version of the cape pattern I used for adult Ezio.

You could also use an online cape tutorials to make your own half-cape. (For example – http://patntf.com/half-circle-cloak-pattern/)
For inspiration, here are a few amazing kids’ Assassin Creed costumes from Pinterest (technically none are of Ezio from AC2: Brotherhood):




I hope this is helpful. If you have any questions, please let me know in the comments. And if you try this, I’d love to see photos.