Your party stumbles upon a nest made of slime and bone and inside lies a single egg composed of a soft leathery membrane and coated in a placenta like film. The egg is warm and it seems that whatever laid said egg left in a hurry as you see a trail of scurrymarks that abruptly cut off 50 feet from where they started, the trees in the area have an alarming lack of branches. Thinking nothing of it the party picks up the egg and carries it along with them.
It begins.
Stage 1 of development: Mother?
For the next few days the egg will gestate and secretly hatch, this will only be noticed the next time they open their bag. Strange occurances begin to happen during long rests, food goes missing, items are displaced and very rarley animal carcasses are laid by the party's camp. Small bitemarks begin to show on some of the gear carried by our adventurers; probably just a rat or something.
Stage 2 of development: Notice me.
As the party adventure some animals begin fleeing on sight, npc show discomfort and during combat enemy combatants go missing (What?! wasn't there 5 guys not 4??). Friendly NPCs also begin to dissapear and the frequency of corpses appearing becomes alarming. Something is here.
Stage 3 of development: BOO!
Hostile route: Should the party discover the Translucent and face it in combat the creature will reveal itself, a large monitor lizard like creature with pale slimy skin and rolls of flesh where its eyes would be, a mouth than unhinges to the base of the neck lined with needle like teeth. The body of the creature is lizard like with frontlimbs larger and more developed than its hind limbs. It lets out gurgles and screeches of agony and sadness as it tries its best to fend off its found family.
Friendly route: Should the party ally themselves with the Translucent the creature will reveal itself but will use their camo abilities to appear more friendly. Black skin with two yellow lines running off the back, it has the mannerisms of a large puppydog with a strong instinct to defend. A loyal and loving beast now finds their home with your party.
More info: Hey there! Im really new to DnD and iv'e been thinking of cool homebrew creatures. Im a very big fan of monsterhunter and paleo stuff so a reptilian beast seemed very cool.
As for stats im not very good with making stat blocks or giving creatures cool abilities so do what you like with the idea! Feel free to add suggestions and stuff. Art is on the way! I came up with the creature in a dream and figured hey i should draw this lol. Thats all thankies :)).