a simple solution

features/animal.feature

@@ -1 +1,23 @@
-#Create your feature here
+Feature: Animal
+  In order to be greeted appropriately
+  I want to track an animal's name
+  I want to track an animal's age
+  I want to track an animal's type
+  I want to know if an animal is old
+
+  Scenario: age
+    Given a animal
+    Then it has a "age"
+
+  Scenario: type
+    Given a animal
+    Then it has a "type"
+
+  Scenario: name
+    Given a animal
+    Then it has a "name"
+
+  Scenario: old
+    Given a animal
+    When age is more than 3
+    Then it should say it is old

features/step_definitions/animal_steps.rb

@@ -1 +1,11 @@
-#Delete this comment, here is where you should write your step defs
+Then(/^it has a "(.*?)"$/) do |attribute|
+  expect(@animal).to respond_to(attribute.to_sym)
+end
+
+When(/^age is more than (\d+)$/) do |age_limit|
+  expect(@animal.age).to be >=  age_limit.to_i
+end
+
+Then(/^it should say it is old/) do
+  expect(@animal.old?).to be true
+end