One in three UK workers admits having lied to take sick leave, according to a survey by PricewaterhouseCoopers.
PwC polled 1,190 people, of which 34% admitted having taken time off under false pretences.
The majority of so-called "skivers" said they did so because they were bored and depressed with work.
Illness is the most common excuse. Four out of 10 said they planned their sick days by faking symptoms around the office in advance.
Some of the more incredible excuses given for missing work included a rabbit running away and amnesia.
About 15% of those who pulled "sickies" said they worked hard and deserved the time off.
"Absenteeism costs British business around £32bn a year, but our findings suggest a large chunk of this loss is preventable," said Neil Roden, a partner at PwC.
For 21% of workers, family was the real reason behind unwarranted sick days.
"Introducing or enhancing flexible working arrangements can make a difference," he added.
"Ensuring people feel they're not taken for granted is also important. Some 15% of those who provided false excuses felt they deserved the time."
Other unusual excuses included breast enhancement, injury during sex, a dart in the back of the head and one person who said their dentist had detected signs of early dementia in their gums.
A Welsh woman took time off because "limescale from the shower fell into her eye".
Pets also provided many of the excuses. One worker said he had to take his dog to the vet - forgetting that he had previously used the excuse that his dog had died.