Grandpa Vlad first came to America with his wife Gladys to start up a restaurant called Yak in the Box in Dimmsdale, which sold Yak meat and become very successful. He is from a small eastern European country called Ustinkistan. He hates his son-in-law, Mr. Turner, and gives him "gifts" that are actually sacks full of vicious weasels.
While Vlad prefers being in America, he still seems to hold the traditions of his homeland fairly close to his heart. At least during the week of Yaksgiving, when he dresses in his native attire and speaks with his native accent. The rest of the year he apparently embraces the American upper-class retiree lifestyle.
Grandpa Vlad bears a slight resemblance to his grandson, Timmy Turner, especially in his younger years where he had brown hair in a style very similar to Timmy's. His eyes are also the same color although a little glossier. He sports the elderly male stereotype of thick, bushy eyeborws. When in his homeland Ustinkistan, and during Yaksgiving, he speaks with a heavy Eastern European accent. This suggests that Timmy takes on mostly from his mother's side of the family.
During normal times in America however, he is actually a very wealthy man who speaks with a snooty accent, wears a white track suit with red lining, and drives a huge golden SUV / RV.
Grandpa Vlad left Ustinkistan with his wife fifty years ago when they were convinced to do so by an "escaped mental patient" (actually a time travelling Timmy Turner), although presumably he would have done so eventually anyways as he ended up in America before Timmy Turner could travel back in time or was even born. He started up Yak in the Box, a fast food yak meat serving restaurant that became highly successful, and he and his wife are actually extremely rich.
Vlad is also the first name of Vlad Tepes AKA Vlad the Impaler, the vicious real-life Bulgarian prince who eventually became the basis for Dracula. There may be a deliberate link , seeing as how Ustinkistan is clearly a parody of countries in the Bulgarian region and Grandpa Vlad likes to inflict pain on Timmy's Dad.
He and Grandma Gladys are the owners of Yak In The Box which is a parody of Jack In The Box.
Denzel Crocker enjoys eating at Yak in the Box regularly.
Timmy's father enthusiastically belives that the sack of weasels and later, the sack of badgers are actually signs that his in-laws have finally come to accept and even love him. This implies that in the past that Vlad and Gladys used to greet him with in an even more vicious and painful manner.
Vlad built a prototype of the visual design for his restaurant out of a turnip.