A stranger was moving in the forest, you passed your stealth check and approach the old camper.

A white beard reaching to bellow his belt, the old man withdraws a long pipe from the top of his gnarled staff. Setting down the staff (which shares his height of 187cm exactly) on a rock to his left. He points his finger at a prebuilt campfire, shooting out a spark to light it up, the fire catching and growing a bit more quickly than you might expect. After some fiddling with his pipe, and muttering a few words to a lazy fat rat lounging on a bed of flowers, your quarry gestures to the fire and a tendril of flame arcs over and lights the pipe.
Furthermore water from the stream leaps into the hanging kettle, only to jump out again into a waiting mug smelling like fresh tea, perhaps with some dried apple in there as well.

Satisfying yourself that this stranger is not a member of the hobgoblin forces you have been contending with you creep closer, trying to get a better look, and there he is reading the initiation papers from SINC, perhaps it's best to get to know him.

In short think Christopher Lee as Saruman if Saruman had laughing lines instead of great power and greater evil. Simple but sturdy white and grey traveling clothes covered by a rich and lovely red woolen cloak and hood. Stuffed in his belt opposite his shortswod is an old pointy wide brim hat a deep wine red colour, darker than the cloak.
The long beard is a stark white and as well kept as the flowing white locks from his full head of hair, complimented by the equally bright white rat.
His voice is kindly and he is a good listener, so long he hasnt dozed off. If you watch Rudolf for some time you may be confused about how such an old man can still look like his is in his prime and so muscle clad.

Rudolf is 79 years young but still has the strength of a young man. If you ask Rudolf he may tell you that it is because he is blessed by the gods of wisdom. If you make him drink truth potion first, he may admit he fell into cauldron of unfinnished frost giant strength as a young lad. This among an evident lack of talent led to him being kicked out of formal magic education in is youth.

A wise man known for his ccompassion, and sometimes-brusque but humorous nature.

Will seek out fun and to satisfy his curiosity even if it can seem to be irrational to others.

Accompanied by a fat white rat most of the time, although odd critters can be seen scuttering around wherever he goes.
Tells many tall tales of unlikely adventures, but occasionally you recognise some actions from supposed adventurers from your grandfathers age. (in human terms.) Likes to read and teach his familiar tricks.