feat(content,port): Add mutated forest creatures

[Zlorthishen]

Purpose of change

Describe the solution

• Add mutated forest creatures. CleverRaven/Cataclysm-DDA#45065

Describe alternatives you've considered

Testing

Additional context

does not port over the iridescent cat, what will be another PR

Checklist

[autofix-ci]

Autofix has formatted code style violation in this PR.

I edit commits locally (e.g: git, github desktop) and want to keep autofix

1. Run git pull. this will merge the automated commit into your local copy of the PR branch.
2. Continue working.

I do not want the automated commit

1. Format your code locally, then commit it.
2. Run git push --force to force push your branch. This will overwrite the automated commit on remote with your local one.
3. Continue working.

If you don't do this, your following commits will be based on the old commit, and cause MERGE CONFLICT.

[chaosvolt]

Eheheheh, Cerbearus

[Lamandus]

looks fine as is, but we also have "mutant organs" I am not sure if other mutants in our game are using regular offal or the mutated version. If not mutated, then it is fine.

[chaosvolt]

I based these off mammal_large_chitin, which has brains and stomach but replaces all other organs with mutant offal at a ratio equal to twice the mass of the brains.

Increasing the mutant offal mass ratios a bit to account for there being fewer organ entries could be done if desired, though probably low priority since generic mutant offal is less useful recipe-wise than generic mutant meat, and probably less useful than any of the individual non-mutant organs either, making it less problematic that you get less of them from scaled bears anyway.