You browsed around a bit and considered the situation. None of this could be real right? What did it matter what you chose? You stopped and looked at what was in front of you, a deer costume. It was somewhat akin to a cheap horse costume made for 2 people, although it was smaller and obviously made for a single person to fit in.
"You know what, you must be bluffing. So I'll take this!" You said to the Crimson Titan.
His eyes went wide and he paled a bit "My good Wallace, that would be quite the life to live. Maybe you should look at the details?".
You decided to, it had some information printed at the top of the package in cheap cardboard. "Live life as a deer in the wilderness! Recommended Settings: 3 years. Male. Body Comfort. Blah-blah-blah" It was more detailed then you cared for, especially for a joke, but you got to the end where it said you could talk to the store manager for a customized experience.
"Yes, I'll take this." You grabbed the package and handed it to him for emphasis.
He took it, sighed, and motioned you to the register area. "You know, I want my customers to be happy, so can I make some suggestions at least on the customizations?" He squinted at you.
"Sure, let's see about ..." You and the Titan went back and forth. When it was done, you went with a 2 year-old female deer, starting in a National Forest somewhere in the western US, and during late Summer, and would remain as the deer for 3 years or until death. As for mental tweaks, you would not feel at home in your body at the start, but eventually both instincts and experience would help you quickly settle into your new body. And speaking for mental changes, your thinking would eventually be limited by the your actual deer brain, but the Titan explained this wouldn't necessarily mean a straight IQ drop or loss of self... unless you didn't bother to try retaining your humanity in some way. He assured it would make more sense as you experienced the life.
As for physical tweaks, you'll be an average 2 year old female deer but these changes were included: You would constantly be in heat even when pregnant or out of season (your choice), you had a hardier immune system (the titan explained you could still get sick, but many past customers complained about dying to more minor things like a cold or wound), pronounced udders with lactation, not effected by diet (your choice but tweaked by the Titan so you wouldn't have to eat more than usual), elastic-but-tight vagina and increased sensitivity on it and the udders(actually rec'd by the Titan so sex would be more fulfilling).
It was an awkward discussion at the beginning, but it felt like you were having a normal transaction as you went through the motions. Soon you purchased the costume, but before you went outside, you wondered about getting into it.
As if reading your mind, the Titan answered it. "Oh it will fit, and no matter where you put it on, you'll end up in the new life, and back where you started when it ends. With that in mind, we do have a changing room in the back..."
You decided to just change in the changing room area, which you found to be like any other in a clothing room store. Soon you were naked, with the deer costume in hand. You felt silly, and still wondered if you should do this...