b'Cryohydra, Elder \n'b'  Family:   Hydra  \n'b'  Huge   monstrosity ,  unaligned  \n'b'  Armor Class  18 (natural armor)  Hit Points  275 (22d12 + 132)  Speed  30 ft., swim 30 ft.\n'b' STATS STR: 22 (+6) DEX:  12 (+1)  CON:  22 (+6)  INT:  2 (-4)  WIS:  10 (+0)  CHA:  7 (-2)  \n'b'\n'b'\n'b'\n'b'\n'b'\n'b'\n'b'  Skills   Perception  +12  Damage Immunities  cold  Senses  darkvision 60 ft., passive  Perception  22  Languages  \xe2\x80\x93  Challenge  20 (25,000 XP) \n'b' Special Traits \n'b'\n'b'  Hold Breath . The elder cryohydra can hold its breath for 1 hour. \n'b'  Multiple Heads . The elder cryohydra has twelve heads. While it has more than one head, the elder cryohydra has advantage on saving throws against being  blinded ,  charmed , deafened,  frightened , stunned, and knocked unconscious. Whenever the elder cryohydra takes 25 or more damage in a single turn, one of its heads dies. If all its heads die, the elder cryohydra dies. At the end of its turn, it grows two heads (up to a maximum of twenty-four heads) for each of its heads that died since its last turn, unless it has taken fire damage since its last turn. The elder cryohydra regains 10  hit points  for each head regrown in this way. If the cryophydra has more than twelve heads, it loses one of its heads when it takes a  long rest . \n'b'  Reactive Heads . For each head the elder cryohydra has beyond one, it gets an extra  reaction  that can be used only for opportunity attacks. \n'b'  Wakeful . While the elder cryohydra sleeps, at least one of its heads is awake. \n'b'\n'b' Actions \n'b'\n'b'  Multiattack . The elder cryohydra makes one Bite  attack  with each head. \n'b'  Bite .  Melee Weapon Attack : +11 to hit, reach 10 ft., one target.  Hit : 11 (1d10 + 6) piercing damage plus 5 (2d4) cold damage. \n'b'  Cold Breath  (recharge 5-6). The elder cryohydra uses all its heads to exhale frost which fills a 30-foot radius sphere centered on a point it chooses within 60 feet of it. Each creature in that area must make a DC 19  Dexterity  saving throw, taking 84 (24d6) cold damage on a failed save or half as much on a successful one.'