Makes the zoglin into a miniboss

It's got full knockback resistance, 100 hp and extra damage.

Now, a half-decent miniboss has drops, the zoglin now drops:
- 5-8 Rotten Flesh
- 3-4 Zoglin Bones (uncommon)
- Rotten Tusk
- Snout Armor Trim (rare)

The Rotten Tusk gives potion effects when drunk. but it's one time use.