There is a strong argument for Attila having Turkic origins.
Hyun Jin Kim noted Attila has more natural and probable Turkic etymology. Omeljan Pritsak considered ̕Άττίλα (Atilla) a composite title-name which derived from Turkic *es (great, old), and *t il (sea, ocean), and the suffix /a/. The stressed back syllabic til assimilated the front member es, so it became *as. It is a nominative, in form of attíl- (< *etsíl < *es tíl) with the meaning "the oceanic, universal ruler".
One of the 19 tribes of Xiongnu, namely Jie people (sometimes Chieh people) migrated toward Kazkhstan in the first half of 4th century. There they mixed withMassagetae (= the Great Yuezhi) tribes and together they moved to Europe. That’s why they were called Huns and Massagetae all together (check Maenchen-Helfen) Actually western Huns were two groups of tribes with different ethnic affinities. Chieh were not leading tribes among Xiongnu. For more check out here:Bulgarians: Origin of Bulgars and Huns
Oh God not another upstart of one of these threads.
"Hunnobulgars.blogspot.bg" is a biased, non-peer-reviewed, inaccurate source.
If anyone wants to know the Origin of the Huns I strongly recommend reading Bona's "Les Huns" if you can find a copy. Otherwise Kims' "The Huns, Rome, and the Birth of Europe," while he has a tendency to find Huns "everywhere", is a great read.
Also check out works by Golden, De La Vassiere, Atwood, etc. etc.
They were a people who probably had some relation to the royal clan of the Xiongnu and were "ethnically" Xiongnu or at least their upper classes were. They originally spoke Yeniseian and then flipped to Oghur in their migration over the Altai mountains. They assimilated and absorbed the Dingling (Tiele Confederation) and were the first wave of proto-Turkic speakers to enter Europe.
As for the "Hun-Bulgar connection"
Eventually their ethnonym Hun began to be replaced by "Bulgar" after a wave of Oghur-speaking peoples attacked the Huns in 460 and mixed with them, resulting in the formation of the Kutrigur/Utigur state above the Pontic. This Hunnish state then collapsed under the Avars and the people assimilated into it as well as newcomers formed the Bulgar confederation some time between 627 and 640 AD. The Bulgars became a predominately Slavic and Slavic speaking people after they emmigrated into the Balkans.
Were they directly related? No. Were they somewhat related? Sort of yes.
I understand their heads didn't look like this naturally, but were the result of the Huns pressing on the skulls of infants with boards to create an odd deformity much in the same way some Central American Indians did.
I know Jordanes described the Huns as having come somewhere East of the sea of Azov. I personally think they were on on move for many years before they arrived in Europe, and were racially a mixed group as many of the fierce Eastern migrations were.