#roe deer

This is most commonly documented in members of the Odocoileus genus, such as these whitetails, and in the Capreolus genus, namely western roe deer. Like the doe above, these deer are typically capable of reproducing, and often behave like other females of their species, i.e. staying in female-only herds. Their heightened testosterone can be linked to hormonal imbalances, malformed or underdeveloped reproductive organs, or tumors/cysts on their ovaries. The latter occurs most often in older individuals, and has also been documented in elk, red deer, and moose (like this cow, which was spotted with a calf near Nome, Alaska).

Alaskan moose (Alces alces gigas)

High testosterone has even been documented in the aforementioned water deer, causing does to grow elongated fangs (DA, OL). These does, like females of other species with permanent velvet antlers, were still capable of producing offspring. While they were expected to exceed the standard weight for does, they were actually smaller.

However, not all antlered does can reproduce, and not all have permanent velvet. In extremely rare cases, their antlers can harden and shed. This leads to the next set of conditions, which unfortunately I don't have pictures for: visibly intersex animals, externally, internally, or both.

A vast majority of visibly intersex deer are discovered via hunting; therefore, intersex whitetails and roe deer (DA) are (still) the best studied. These deer can have any combination of sex organs, such as an individual with a vulva, cervix, testes, and more (DA, OL). Their antlers can be velvet or hardened, though they're often malformed. They may exhibit behaviors of both sexes, including breeding behaviors; while I couldn't find much regarding their reproductive ability, most are likely infertile. There's still a lot to study regarding these guys, especially in poorly-researched species like muntjacs, brockets, and hog deer.

Finally, the most common form of intersex in deer: cryptorchidism. This is a condition where one or both testicles don't descend properly, or are otherwise malformed. It causes male deer to grow wonky antlers, referred to as "cactus antlers," "Devil's antlers," and, for moose, velericorn antlers (also used for antlered cow moose). They shed them at odd times, and, like for this individual, they might even crumble away rather than pop off cleanly.

White-tailed deer (Odocoileus virginianus) (OL)

These deer may have little interest in mating, scraping, self-urinating or other breeding behaviors due to a lack of testosterone, or even prefer the company of females year-round. They may look more feminine, like this elk found in Jackson Hole, Wyoming, which I believe to be a bull with cryptorchidism or another hormonal imbalance.