Beginning his involvement with the Muppets in 1978,[3] Whitmire inherited the roles of Ernie and Kermit the Frog after Jim Henson's death in 1990; he performed the characters until 2014 and 2016, respectively.

Before graduating high school, Whitmire had his first "professional" puppeteering job using Otis at "The World of Sid & Marty Krofft" in Atlanta, the first indoor theme park.

From there Whitmire appeared on local Atlanta TV live for 2 1/2 hours every day on "The Kids Show with Otis" taking telephone calls from children and adults.

Otis made appearances on various WATL 36 shows with Atlanta's Ludlow Porch, performing with the Georgia Bulldogs' Larry Munson, Don Kennedy, and Entertainment Page host Artie Goodman.

In their decision-making, The Muppets Studio's parent company Disney consulted the Henson family, who supported the recasting of Kermit and Whitmire's dismissal.

[7] Lisa Henson stated that Whitmire was opposed to having an understudy for Kermit and refused to train one, which became problematic when it came to "B-level performances, such as a ribbon-cutting," at some of which she said he was unwilling to appear.

[17] In a statement released to The New York Times, Debbie McClellan, then-head of The Muppets Studio, said that they "raised concerns about Steve’s repeated unacceptable business conduct over a period of many years, and he consistently failed to address the feedback".