Merman

Aquatic humanoids with fish tails in place of legs. Live in coastal waters, farming seaweed and hunting fish.

AC6 [13], HD1 (4hp),
Att 1 × weapon (1d6 or by weapon), THACO 19 [0],
MV 120’ (40’), SV D12 W13 P14 B15 S16 (1),
ML 8, AL Neutral, XP 10 (leader: 20/75), NA 0 (1d20), TT A

• Weapons: Spears, tridents, or daggers.
• Leaders: For every 10 in a group, there is a 2HD leader. For every 50, there is a 4HD leader (saves: D10 W11 P12 B13 S14 (4)).
• Underwater villages: Home to 1d3 × 100 individuals.
• Guardians: Use trained sea creatures or monsters to guard their homes.

Source: Classic Fantasy