make what you want of this, make only the changes that make sense to you.
OK, differences between your version and what i got from the 2E FF:
give it a burrow speed of 30 ft
i gave it tremorsense instead of blindsight (it also communicates through vibrations)
it’s still a shy and peaceful creature, but when it needs to fight, it has a combination trip/acid attack: the denzelian exudes an acid from its skin (entire body surface) that does 5d4 points of acid per round, which even allows it to move through rock. (sort of a dissolve and slide movement, or sinking into it) to attack, it will rush and opponent, causing him to trip and fall on top of the creature, thereby taking acid damage to him and his gear. Reflex save means half damage (DC should probably be pretty low, since the dezny is slow).
It’s not clear whether they can dissolve metal or not, but they don’t eat metal so I’d say probably not.
it also has a crush attack: it can burrow through rock above a creature, then eat through the floor and drop onto a creature. It weighs nearly 1000 pounds and deals 4d6 damage to anything caught underneath (another reflex save). If trapped, creatures also automatically take acid (and crushing?) damage in the next and following rounds. The denzelian is flexible enough that trapped creatures do not suffocate.
When the denzy dissolves rock with its acid, it leaves a crumbly, blackish, sandlike residue behind. When it makes its dropping crush attack, this gritty substance fills the air in a 10 foot radius of the denzy. It gets in the eyes, nose, and mouth of nearby creatures, who must make a fort save or suffer a –2 to attack rolls for 1d4+1 rounds (or when the substance is washed away).
I guess the 2E designers figured the denzy wasn’t anywhere near as powerful as it should have been, so they beefed it up quite a bit.
