Beast's Revenge

Siege Monster. The beast's revenge deals double damage to objects and structures.

Legendary Resistance (3/Day). If the beast's revenge fails a saving throw, it can choose to succeed instead.

Magic Resistance. The trench beast has advantage on saving throws against spells and other magical effects.

Reflective Carapace. Any time the beast's revenge is targeted by a magic missile spell, a line spell, or a spell that requires a ranged attack roll, roll a d6. On a 1 to 5, the beast's revenge is unaffected. On a 6, the beast's revenge is unaffected, and the effect is reflected back at the caster as though it originated from the beast's revenge, turning the caster into the target.

Gamma body: Beast's revenge attacks gain an additional (3d10) radiation damage. and they count as magical in order to overcome resistances.

Multi-attack. The trench beast can use its Frightful Presence. It then makes five attacks: two with its bite, two with its claws, and one with its tail.

Bite. Melee Weapon Attack: +44 to hit, reach 20 ft., one target. Hit: 116 (12d12 + 30) piercing damage. If the target is a creature, it is grappled (escape DC 20). Until this grapple ends, the target is restrained, and the trench beast can’t bite another target.

Claw. Melee Weapon Attack: +44 to hit, reach 30 ft., one target. Hit: 100 (12d8 + 30) slashing damage.

Tail. Melee Weapon Attack: +44 to hit, reach 40ft., one target. Hit: 92 (12d6 + 30) bludgeoning damage. If the target is a creature, it must succeed on a DC 20 Strength saving throw or be knocked prone.

Frightful Presence. Each creature of the trench beast choice within 300 feet of it and aware of it must succeed on a DC 19 Wisdom saving throw or become frightened for 4 minutes. A creature can repeat the saving throw at the end of each of its turns, with disadvantage if the trench beast is within line of sight, ending the effect on itself on a success. If a creature’s saving throw is successful or the effect ends for it, the creature is immune to the trench beast's Frightful Presence for the next 24 hours.

Element beam: Ranged Weapon Attack: +44 to hit, range 20/600 ft., multiple targets. Hit: 148 (12d12 + 40) [radiation] damage.

Surprise Gamma Ray. Whenever anything makes an attempt at attacking the Beast's Revenge, it may shoot and instantaneous Element beam.

Shake off: if a creature grabs onto or gets near it this creature, using a reaction will shake violently throwing of anything attached to it or knocking them away with it's body.

Lunge: If a creature gets in front of it the trench beast will lunge forward at them and either bite them or swallow them. It may also claw them instead

Sonic roar: When damaged the trench beast may use a reaction and roar loudly knocking back all creatures in range and dealing (1d6) bludgeoning damage.

The beast's revenge can take 4 legendary actions, choosing from the options below. Only one legendary action option can be used at a time and only at the end of another creature’s turn. The beast's revenge regains spent legendary actions at the start of its turn.

Attack. The trench beast makes one claw attack or tail attack.

Move. The trench beast moves up to half its speed.

Chomp (Costs 2 Actions). The trench beast makes one bite attack.

As the Beast's revenge exists the gamma radiation generated from its body will start to gather around it creating a semipermeable shell across its entire structure which it can then use for certain actions or make other actions stronger. (using these actions decreases the amount of radiation charged by the same amount of what the action required)

Gamma Spikes (after 10 minutes). The radiation shell hardens on certain parts of the body and creates spike-like protrusions that will damage anything that touches them for (2d8) radiation damage.

Gamma boost (after 25 minutes). Taking some of the radiation the monster will charge it into a certain part of its body granting an attack with that body part an additional (2d10) radiation damage.

Gamma flash (after 30 minutes). Using about half of the stored energy the beast's revenge will create a flash of light that blinds everything except the Beast's revenge for 5 turns unless they make a DC 20 CON saving throw.

Gamma jet (after 45 minutes). The creature shoots out concentrated gamma blasts out its body to give itself a 50% speed boost

Shin G Blast (after 50 minutes). The monster, using up most of the radiation begins shooting Element Beams out of random parts of its body that move around on their own for 1 minute.

Gamma Discharge (after 1 hour). Using all the stored up gamma radiation coating its body the Beast's revenge will release it all at once creating an explosion stretching out 10 km out from the monster killing everything it touches.