Llamas in the sims and other ongoing jokes

I like seeing the llama and freezer bunny throughout all the different games. They are a fun inside joke to the long time players. I love the gnomes from ts3. They were fun to collect and you could even have a little gnome family that aged and grew along with your sims if you had two normal gnomes on your lot. The baby and toddler gnomes were adorable.

Edit: Also may not be an easter egg per se but two food items that tend to be popular with the sims team are grilled cheese and goopy carbonara. Though I don't think goopy carbonara is in ts4.