Yes, I said entity instead of character. Halloween happens on 31 October. What entity from the "Eric & Yannik" games do you want to dress up as for Halloween? Here are some choices (taken from the newest "Eric & Yannik" game):

From topleft to topright to bottomleft to bottomright:
- Eric
- Yannik
- Glaber Worker
- Glaber Queen
- Green Slime
- Wooden Crate
- Plasma Snotter
- Plasma Pigasnotter
There may be more entities from the "Eric & Yannik" games you want to dress up as for Halloween that aren't listed on this post.