diff --git a/src/__phutil_library_map__.php b/src/__phutil_library_map__.php
--- a/src/__phutil_library_map__.php
+++ b/src/__phutil_library_map__.php
@@ -135,6 +135,8 @@
     'PhutilConsoleTable' => 'console/PhutilConsoleTable.php',
     'PhutilConsoleWrapTestCase' => 'console/__tests__/PhutilConsoleWrapTestCase.php',
     'PhutilContextFreeGrammar' => 'grammar/PhutilContextFreeGrammar.php',
+    'PhutilCowsay' => 'utils/PhutilCowsay.php',
+    'PhutilCowsayTestCase' => 'utils/__tests__/PhutilCowsayTestCase.php',
     'PhutilCsprintfTestCase' => 'xsprintf/__tests__/PhutilCsprintfTestCase.php',
     'PhutilCzechLocale' => 'internationalization/locales/PhutilCzechLocale.php',
     'PhutilDaemon' => 'daemon/PhutilDaemon.php',
@@ -643,6 +645,8 @@
     'PhutilConsoleTable' => 'Phobject',
     'PhutilConsoleWrapTestCase' => 'PhutilTestCase',
     'PhutilContextFreeGrammar' => 'Phobject',
+    'PhutilCowsay' => 'Phobject',
+    'PhutilCowsayTestCase' => 'PhutilTestCase',
     'PhutilCsprintfTestCase' => 'PhutilTestCase',
     'PhutilCzechLocale' => 'PhutilLocale',
     'PhutilDaemon' => 'Phobject',
diff --git a/src/utils/PhutilCowsay.php b/src/utils/PhutilCowsay.php
new file mode 100644
--- /dev/null
+++ b/src/utils/PhutilCowsay.php
@@ -0,0 +1,135 @@
+<?php
+
+/**
+ * Parser and renderer for ".cow" files used by the `cowsay` program.
+ */
+final class PhutilCowsay extends Phobject {
+
+  private $template;
+  private $eyes = 'oo';
+  private $tongue = '  ';
+  private $action = 'say';
+  private $text;
+
+  public function setTemplate($template) {
+    $this->template = $template;
+    return $this;
+  }
+
+  public function setEyes($eyes) {
+    $this->eyes = $eyes;
+    return $this;
+  }
+
+  public function setTongue($tongue) {
+    $this->tongue = $tongue;
+    return $this;
+  }
+
+  public function setAction($action) {
+    $this->action = $action;
+    return $this;
+  }
+
+  public function setText($text) {
+    $this->text = $text;
+    return $this;
+  }
+
+  public function renderCow() {
+    $width = 40;
+    $template = $this->template;
+
+    // Real ".cow" files are Perl scripts which define a variable called
+    // "$the_cow". We aren't going to interpret Perl, so strip all this stuff
+    // (and any comments in the file) away.
+    $template = phutil_split_lines($template, true);
+    $keep = array();
+    foreach ($template as $key => $line) {
+      if (preg_match('/^#/', $line)) {
+        continue;
+      }
+      if (preg_match('/^\s*\\$the_cow/', $line)) {
+        continue;
+      }
+      if (preg_match('/^\s*EOC\s*$/', $line)) {
+        continue;
+      }
+      $keep[] = $line;
+    }
+    $template = implode('', $keep);
+
+    $template = preg_replace_callback(
+      '/\\$([a-z]+)/',
+      array($this, 'replaceTemplateVariable'),
+      $template);
+    if ($template === false) {
+      throw new Exception(
+        pht(
+          'Failed to replace template variables while rendering cow!'));
+    }
+
+    $lines = $this->text;
+
+    // TODO: It would be nice to use a utf8 soft wrap here instead, but we
+    // do not currently have one. Soft wrap first, then force to utf8.
+    $lines = wordwrap($lines, $width - 4, "\n", true);
+    $lines = phutil_split_lines($lines, false);
+    foreach ($lines as $key => $line) {
+      $lines[$key] = phutil_utf8ize($line);
+    }
+
+    if ($this->action == 'think') {
+      $borders = '((()))';
+    } else {
+      if (count($lines) == 1) {
+        $borders = '<<<>>>';
+      } else {
+        $borders = '/|\\\\|/';
+      }
+    }
+
+    $size = 0;
+    foreach ($lines as $line) {
+      $size = max(strlen($line), $size);
+    }
+
+    $balloon = array();
+    $balloon[] = ' '.str_repeat('_', $size + 2);
+    $lines = array_values($lines);
+    $last = (count($lines) - 1);
+    foreach ($lines as $idx => $line) {
+      if ($idx == 0) {
+        $l = $borders[0];
+        $r = $borders[3];
+      } else if ($idx == $last) {
+        $l = $borders[2];
+        $r = $borders[5];
+      } else {
+        $l = $borders[1];
+        $r = $borders[4];
+      }
+      $balloon[] = $l.' '.str_pad($line, $size).' '.$r;
+
+    }
+    $balloon[] = ' '.str_repeat('-', $size + 2);
+    $balloon = implode("\n", $balloon);
+
+    return rtrim($balloon."\n".$template);
+  }
+
+  public function replaceTemplateVariable($matches) {
+    switch ($matches[1]) {
+      case 'eyes':
+        return str_pad($this->eyes, 2);
+      case 'tongue':
+        return str_pad($this->tongue, 2);
+      case 'thoughts':
+        return ($this->action == 'say' ? '\\' : 'o');
+      default:
+        return $matches[0];
+    }
+  }
+
+
+}
diff --git a/src/utils/__tests__/PhutilCowsayTestCase.php b/src/utils/__tests__/PhutilCowsayTestCase.php
new file mode 100644
--- /dev/null
+++ b/src/utils/__tests__/PhutilCowsayTestCase.php
@@ -0,0 +1,60 @@
+<?php
+
+final class PhutilCowsayTestCase extends PhutilTestCase {
+
+  public function testCowsay() {
+    $dir = dirname(__FILE__).'/cowsay/';
+    $tests = array();
+    foreach (Filesystem::listDirectory($dir, false) as $test) {
+      if (preg_match('/\.test\z/', $test)) {
+        $tests[] = $test;
+      }
+    }
+
+    foreach ($tests as $test) {
+      $data = Filesystem::readFile($dir.$test);
+      $expect = preg_replace('/\.test\z/', '.expect', $test);
+      $expect = Filesystem::readFile($dir.$expect);
+
+      $pattern = '/^~~~+$/m';
+
+      if (!preg_match($pattern, $data)) {
+        throw new Exception(
+          pht(
+            'Expected cowsay test file "%s" to contain a line of tildes '.
+            'separating the template from the test parameters.',
+            $test));
+      }
+
+      list($template, $spec) = preg_split($pattern, $data, 2);
+      $spec = phutil_json_decode($spec);
+
+      $cowsay = id(new PhutilCowsay())
+        ->setTemplate($template);
+
+      if (idx($spec, 'text') !== null) {
+        $cowsay->setText($spec['text']);
+      }
+
+      if (idx($spec, 'eyes') !== null) {
+        $cowsay->setEyes($spec['eyes']);
+      }
+
+      if (idx($spec, 'tongue') !== null) {
+        $cowsay->setTongue($spec['tongue']);
+      }
+
+      if (idx($spec, 'action') !== null) {
+        $cowsay->setAction($spec['action']);
+      }
+
+      $actual = $cowsay->renderCow();
+
+      $this->assertEqual(
+        rtrim($expect),
+        rtrim($actual),
+        pht('Cowsay Test Case "%s"', $test));
+    }
+  }
+
+}
diff --git a/src/utils/__tests__/cowsay/cube.expect b/src/utils/__tests__/cowsay/cube.expect
new file mode 100644
--- /dev/null
+++ b/src/utils/__tests__/cowsay/cube.expect
@@ -0,0 +1,12 @@
+ __________________
+( I made a friend! )
+ ------------------
+ o
+  o
+    /---\__/---\\
+    | / .... \ ||
+     \ ..--.. //
+     |..(<3). ||
+     / ..--.. \\
+    | \ .... / ||
+    \---/--\---//
diff --git a/src/utils/__tests__/cowsay/cube.test b/src/utils/__tests__/cowsay/cube.test
new file mode 100644
--- /dev/null
+++ b/src/utils/__tests__/cowsay/cube.test
@@ -0,0 +1,15 @@
+ $thoughts
+  $thoughts
+    /---\__/---\\
+    | / .... \ ||
+     \ ..--.. //
+     |..($eyes). ||
+     / ..--.. \\
+    | \ .... / ||
+    \---/--\---//
+~~~~~~~~~~
+{
+  "text": "I made a friend!",
+  "action": "think",
+  "eyes": "<3"
+}