Description - Like a humanoid rot-fish the deep ones get their power from the sea. Immune to acid. Deep Ones are melee capable but generate spikes to shoot at the player when in contact with water or acid.
Water Abilities - They can move very fast in water, able to jump extremely high out of water, gain the ability to spit acid while in even a little bit of acid, spikes when they are in water or leaping from either and 1/2 damage from explosives while in touching water. They are extremely weak to the lightning gun while in water.
Out of water abilities - Out of water they move slower, can leap similar to, although shorter distances then, the fiend, will spend most of their time navigating back to water, BUT are no longer extremely weak to the lightning gun.
The idea is to push for more interesting gameplay. The player will have to try and keep these types of creatures away from their "power" source or have to wait a second for a patrolling creature to step out of the water in order to get the jump on them. Mappers can design levels that the player can "force" themselves through an area surrounded by water, or find a button that drains the water first, making combat easier for the player who uses their head.
Other ideas include: creatures that actually heal when exposed to the lightning gun or explosives, creatures that gain similar abilities when exposed to lava, an enemy that changes into another creature based on how you kill it (like a that gets blown up and forms smaller creatures), enemies with "weak points" or even a creature that is only able to be damaged by the Axe. None of these will be made too extreme, Quake is about the action and to break that up too much would be a sin. The point is to create creatures that can potentially increase the chaos drastically if the player isn't careful mid-combat.
Just throwing around some ideas for creatures and things. I am hoping for a concept of a couple monsters in a month or two. I am just wondering what other people think of this kind of concept?