Rat of Really Unusual Size (3.5e Monster)

''What are the rats eating in this flogging sewer? Cheese? Where are they getting cheese that turns them into these freaking RORUS!''

The Rat of Really Unusual Size (Behemothian Dire Rat or RORUS) is a freak occurrence of titanic spark occurring in your normal dire rat. Already too large for a rat, the RORUS towers over most buildings and dwarfs former predator, resulting in a bold and ravenous monster seeking endless nourishment.

Because the RORUS has increased in size seven times, its effective HD is 22.

Combat
Rats of truly terrifying size, they are usually unable to fit in their sewer homes and quickly rampage across the surface, trying to feed their proportionally large appetites.

Disease : Filth fever—bite, Fortitude DC 23, incubation period 1d3 days, damage 1d3 Dex and 1d3 Con. The save DC is Constitution-based.

Massive Body : The massive body of a behemothian creature makes it immune to death from massive damage and death effects. It also gains a +4 bonus on saves against poison.

Its massive body is also a downside, as creatures three sizes or smaller (Large or smaller) can scale its body as if it were mobile terrain. Such creatures can make a grapple check against a DC of 20 to grab on. The smaller creature is considered grappling but the behemothian creature is not. The smaller creature enjoys soft cover while in this space but is also typically flatfooted. A behemothian creature can dislodge the climbing offending creature with its Shake Off ability, or by making a successful grapple and pin attempt against its climbing adversary.

Finally its massive bulk reduces the effect of spells and effects affecting it. There's just too much to effect. For each size category the creature rises by, the creature gains a +1 circumstance bonus to all saving throws.

Shake Off : If a smaller being is climbing a behemothian dire rat, the behemothian can shake it off as a move action by vibrating its body violently. The behemothian dire rat makes a a check of the dire rat's BAB + Strength, opposed by the grappling dire rat's climb check. If successful, the behemothian dire rat throws off the climbing opponent, launching them 1d6x10 feet in a random direction and dealing appropriate falling damage.

Titanic Blow : Every hit from the behemothian dire rat is like getting hit with a ton of bricks. A behemothian dire rat which strikes in melee can choose to make a free bull rush attempt without provoking. If successful, the opponent is knocked back without the behemothian dire rat needing to follow it, and falls prone in its spot.

Titanic Stomp : As a standard action the behemothian dire rat can strike at the ground and cause opponents to tumble down. All opponents within a 20 foot burst must make a Reflex save (DC 36) or fall down prone and take 9d4 nonlethal damage, save negates.

Trample : A behemothian dire rat gains the trample ability. It deals 6d6+39 damage, Reflex DC 36.

Worldshaker : The sheer size of a behemothian creature causes the ground to quake as it passes. All those within 10 feet of a moving or burrowing behemothian creature must make DC 15 Balance checks, or fall prone. No matter how many times a behemothian creature passes a creature need only make the check once.

Flying behemothian creatures that fly with wings have a similar effect, but instead create a billowing windstorm around them which duplicates the effect of severe wind in 10 feet while it is flying by or hovering.

Swimming behemothian creatures also disrupt their environment. All those within 10 feet have the water churned into stormy water (a DC 20 Swim check) if not already worse.

Skills:  Behemothian dire rats have a +8 racial bonus on Swim checks. They have a +8 racial bonus on Climb checks and can always choose to take 10 on Climb checks, even if rushed or threatened.

Behemothian dire rats can choose use their Dexterity modifier for Climb and Swim checks, but rarely do thanks to their massively increased strength.