Final answer:
The tattoo design would be subjective and up to Calvin's individual taste
Step-by-step explanation:
The question is asking about the tattoo that Calvin had put on his ankle for his birthday.
As an arts question, the specific tattoo design is not mentioned. Tattoos can vary widely in design and style, and it would depend on Calvin's personal preference or significance. Some examples of popular tattoo designs include animals, symbols, quotes, and geometric patterns.
Overall, the tattoo design would be subjective and up to Calvin's individual taste.