---

All answers having "Twain hero" as clue:

3 Character Answers:

---

TOM



4 Character Answers:

---

FINN

HUCK

KCUH



5 Character Answers:

---

CANTY



6 Character Answers:

---

SAWYER



15 Character Answers:

---

HUCKLEBERRYFINN

PUDDNHEADWILSON