Underworld beasts 04 - Portal Horrors

Gearing up for Christmas holidays (possibly last one) and trying to get back into reading and writing and editing some of my failed projects. Has been good year for health, work, pay and artwork. Not such a prolific game year. Ive never been a big dnd monster maker or blogger maker since a teen. I will re create those early monsters. Dragon did some good undead i need to dig up - bloody bones and even some fallout ghouls would be cool. Any feedback on these monsters?

Underworld beasts 04 - Portal Horrors
These beasts follow the dungeon ecology niche as a flat chameleon ambush predator. They remove and replace existing doors, gates, curtains in dungeons and occasionally eating someone. Some use out of the way passages off main routes. Others are more blatant living in busiest areas or even leaving the dungeon and moving to bigger owns. Some set themselves against solid rock wall in a room teasing visitors with a strange new door.

Usually they will wait for someone to be passing through the portal when they get +4 o hit by surprise like a thief. At that moment they become a fluid mass of mouth surrounded by eye stalks and tentacles. Their teeth are metallic. The usually eat once a week to keep happy or a month if desperate. If fattening up or pregnant it may eat daily for up to a week then sleep for a week. They will eat wood, stone, plaster but only if moving to new position.

Their flesh is wood like and and their bones are metallic. They most often appear as a iron bound oak door. Some smaller ones or infants appear as trapdoors, well covers, barrel lids, box tops. They scuttle about flat on the ground and slide under the adults who let them in anywhere. Strong adults always stand 90degrees to the ground. They all can spawn 2d10 babies a year but require a mate. Mostly they avoid each other.

You may be able to use them with no problem like a normal gate if well fed. Some make deals for a weekly sacrifice of food to act as guards for important rooms. Some dungeon bosses use them and move them around. Some cults know how to use them. Trickster cultists say sacred monster doors are a great gag that proves gods exist.

Portal Horrors prefer to ambush people passing through them but they will react badly instantly to anyone attempting to pick their keyhole eye. Trickster doors really dislike battering rams, tiny cannons, building fires on it or pretty much any siege technology. They are suspicious of wizards. They are quite adept at letting the first spell, ram or missile pass through them if they sacrifice a move or attack. They are smart enough to let a battering ram harmlessly through then bite hands off guys in front. Some might attack the ram taking it then chasing users. If they are persistently attacked they will move and change shape.

Trapdoor Horrors
AC +5 HD 1d8+4 MV3"crawl Bite d8 SA: Bitten victim trapped STR12
Under five year olds fairly common and a bit dim.

Portal Horrors
AC +8 HD 3d8+4 MV9"crawl Bite 2d8 SA: Bitten victim trapped STR18
Standard beast are sentient beings without complex language that understand human methodology

Gatehouse Horror
AC +10 HD 16d8+4 MV6"crawl Bite 5d8 SA: Bitten victim trapped STR22, bite all in line area fx
Great ancient ones guard mighty things and are also 12th level Priests with inhabitant followers inside including other shape shifting trap monsters or cultists.

When a horror bites a victim they get a STR save or are trapped in the creature mouth and it will eat them if alone or retreat dragging its victim away if outnumbered. The victim trapped gets a second save to be able to use weapons or abilities while held. The whole time it holds it chews the victim for a automatic bite attack each round. Gatehouse horrors can be 5" wide and can bite any target in a line the width of the gate mouth.