Identify the following parasites and the phylum to which they belong.
It invades the skin of humans and causes elephantiasis.

Explanation

**Step-by-Step Solution:**

1. **Identify the Parasite**: The question states that the parasite invades the skin of humans and causes elephantiasis. The specific parasite responsible for this condition is known as the filarial worm.

2. **Scientific Name**: The scientific name of the filarial worm that causes elephantiasis is Wuchereria bancrofti.

3. **Determine the Phylum**: Filarial worms, including Wuchereria bancrofti, belong to the phylum Nematoda. This phylum is commonly known as the roundworms.

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