seem like an error

https://mods.factorio.com/mod/psyduck?from=updated

I'll look into it!

By the way, your changelog entries are not really useful if all you put in them is "Fix issues and optimize multiple details". Be a bit more specific! For example, it would be useful to know what version introduced the CMH dependency to Psyduck, or when you changed animations, armor, localization etc. I, at least, assume that a mod update will fix bugs, or optimize certain things, or add new features – but I'd like to have a general idea what changes I have to expect when I download the update. A default sentence that is so general that it applies to every version doesn't help at all. With more details, the changelog can help you remember what changes you've made in a particular version (possibly also explaining why you've made those changes) – and your users can see what improvements you've made over time.

The improvement is not that big. I really don't know how to write it, so I just wrote it like this.

Also, I think the name of your mod is too long, that's what should be in the description.

The reason for the buggy string is your definition in __psyduck__/character_creator.lua:

 corpse.localised_name = { "", "entity-name." .. corpse.name, "entity-name.corpse" }
 corpse.localised_description = { "entity-name." .. corpse.name }

The first value in a locale string is the template to use, subsequent values are arguments to be used in parametrized strings. In the localised description, the template is psyduck-skin-corpse in section entity-name. For localised_name, the first value is an empty string. This will bypass the strings found in the locale file (there is no section ""), so the empty template is used and all subsequent values will be concatenated.