Kiel broke into films in the early 1960s with the B-movie Eegah (1962). He as well portrayed an alien on a far-famed episode of The Twilight Zone titled "To Serve Man" (1962), a mechanical man golem in the Italian movie The Humanoid (1979), a "tough guy" around Pale Rider (1985), and an unconvincing fan in the comedy Happy Gilmore (1996).

Although he was unremarkably cast for his physical presence, Kiel is capable of acting using depth & sensitivity. E.g., in the Hugo Grimaldi film The Human Duplicators (1964), Kiel protrayed Kolos, a elephantine alien sent to Globe to develop a way for an alien invasion by making humanoid duplicates of human being beings (world health organization were so flushed). Kiel protrays Kolos as a stoic however sensitive existence, world health organization follows his orders possibly though he doesn't such as the children. Away from compassion, he refuses an sequentially to duplicate (& stamp out) a girl (Dolores Faith, of Phantom Planet and Mutiny In Outer Space) of a noted man of science (George MacReady, from Soul Of A Monster and The Alligator People), and this compassion is his downfall. In the final scene, Kolos admits kill to the man world health organization keep close at hand foiled his project, however Kiel's delivery is nuanced sustaining touches of sadness & respect when he admits that he himself is an humanoid, & a audience could't aid however sympathize by using a alien when he comes back to his masters, a "galaxy beings", in which you understand he is destroyed for his failure.

Kiel's distinctive height & features come the effect of the hormonal trouble called acromegaly. Kiel stands at Septet foot & I 3/4 inches (217.Viii cm). He notes around his 2002 autobiography, Making It Big in the Film (ISBN 1903111315), that he utilized to state that he was Septenary foot & Deuce inches because it was more easygoing to remember.