Booming Boars

A bit of confusion today, I think purely due to my own curtness, as to whether I think giant boars are a good idea for a monster or not. As penance I'll post what I've been working on today a bit earlier than planned. Everything in the quote box below is designated as Open Game Content, as per the Open Game License Version 1.0a:

BOOMING BOARS

Number: 1-6
Armor Class: 5
Move: 15"
Hit Dice: 5
% in Lair: Nil
Treasure Type: Nil
No. of Attacks: 1
Damage: 1d6+2

Booming boars appear to be large but possibly normal boars or warthogs, 4' high at the shoulder. However, they have an explosive sonic/belching attack that can affect anyone in a cone-shaped area 6" by 3". Targets must save versus paralysis or become deafened (1d6 turns) and stunned (1d3 rounds). Individual boars can only belch once per day, but those in a group (called "sounders") may stagger their sonic attacks over several rounds (roll 3-in-6 for each boar to belch in any round). They are themselves immune to sonic attacks.