“Quicker than you can spit and holler ‘Howdy!’”

“Quicker than you can spit and holler ‘Howdy!’” is very fast. It’s not known if this phrase originated in Texas.
 
 
Google Books
The Old -Time Cowhand
by Ramon F. Adams
1948, 1949, 1951, 1954, 1959, 1960, and 1961
Originally published: New York: Macmillan, 1961
First Bison Book Printing: 1989
Pg. 35:
If they’d been able to understand the words, more’n likely they’d quit the bedground quicker’n you could spit and holler howdy.
 
16 December 1955, Atkinson (KS) Daily Globe, pg. 4:
Like Grandpa Sandy says, “Before I could spit and holler howdy, it was gone.”
 
Uncle John’s Bathroom Reader
Plunges Into Texas
by The Bathroom Readers’ Hysterical Society
San Diego, CA: Portable Press
2004
Pg. 157 (Cowboy Talk):
“Quicker ‘n you can spit ‘n holler ‘Howdy!’”
Very fast.