I own a content-management system which uses Cake's inflector to output entries with pluralization if I detect there's more than one available.
if ($amt >= 2)
$object_name = Inflector::pluralize($object_name);
This works well for any object so long as it isn't in the Inflector's "irregular" list.
http://inflector.cakephp.org/The%20Purple%20Cow returns "The Purple Tows" http://inflector.cakephp.org/Purple%20Cow returns "Purple Pows" http://inflector.cakephp.org/The%20Purple%20Goose returns "The Purple Teese" http://inflector.cakephp.org/Purple%20How returns "Purple Hows" as expected
For some reason it's substituting the last word's first letter with the first word's first letter, then adding an S as expected.
UPDATE: CakePHP bug, documented here. Will be fixed in 2.6.5. Question has been modified to avoid confusion.
Seems to be a bug specific to the word Cow in the last position. "The Purple Hen" and "Purple Hen" work fine. "Cow Fence" works fine. But "Big Cow" or "The Big Cow" reproduce the bug.
I would recommend looking into opening a ticket using their guidelines here.
You'll need to search existing tickets related to the inflector to see if it has already been reported. There are several other inflector issues, but I didn't find anything when searching for the term cow.