Derek McGlone, 42, a head of department at Calderhead High School in Shotts, North Lanarkshire, also went on a drunken rant on Facebook where he called other staff "bitches."
His former colleagues complained his comments were abusive and threatening.
In another bid to get time off work, Mr McGlone told a deputy head he was caught up in Iceland's ash cloud which grounded thousands of flights in 2010, despite being at home in Glasgow.
He represented himself at a disciplinary hearing of the General Teaching Council Scotland (GTCS) yesterday, which found his fitness to teach was impaired.
A reprimand has been recorded in the teaching register against Mr McGlone's name for 12 months.
He said he was embarrassed and sorry about his actions, but insisted he still wanted to teach because he had a "passion" for the profession.
Mr McGlone admitted three charges brought by the GTCS, including making threatening and abusive comments towards former teaching colleagues on Facebook between June 9, 2008, and May 31, 2011.
GTCS solicitor Niall McLean read out a statement from deputy head teacher at Calderhead High, Joyce Kilmartin.
She said there was a number of occasions Mr McGlone had lied in order to take days off work. Her statement added: "He started off telling a few silly lies. He lied about knocking a girl over and killing her. He said he felt his car wheels running over her body."
The hearing was also told of Mr McGlone's messages directed towards former colleagues on Facebook.
Mr McLean said Mr McGlone called former colleagues "bitches" and said he was going to "hunt them down".
In one post he wrote: "The challenged are threatened by the gifted."
Mr McLean added: "The posts were abusive and threatening in nature.
"He was dishonest in his dealings with his employers."
Mr McGlone said he had been a respected head of music, art and design at Calderhead High when he made false statements about his absence in June 2008 and April 2010.
He admitted he had lied in order to take time off work and that he had written abusive comments on Facebook after leaving the school.
He said: "I can give no reasonable explanation for my actions. I make no excuse for any of the three incidents.
"They are unforgivable, stupid and silly. Please believe me I have had enough time to think about this."
Mr McGlone said he had taken to Facebook in April 2011 in a "drunken rant" after discovering former colleagues had made statements about him to the GTCS.
He said: "I was dumbfounded and horrified at reading the statements made by staff.
"I cannot explain how embarrassed and how sorry I feel about the comments being taken as threatening.
"I do not consider myself to be a threatening person. People would laugh if they heard me described as threatening."
He added: "I do admit wholeheartedly the case against me and I have been previously of good character.
"Nothing of these matters will happen again."
Mr McGlone said he had been involved in touring productions of Evita and Scrooge since resigning from the profession last year.
He said: "I have always had a passion to teach.
"I have tried to make a living doing other things but there is nothing that compares to teaching."
The hearing panel concluded that Mr McGlone's conduct "fell short of the standards expected of a registered teacher and that his fitness to teach is therefore impaired".
However, it considered that removing his name from the register would be "disproportionate to the seriousness of the complaints".
Instead a reprimand was recorded in the register against Mr McGlone's name for a period of 12 months.
A spokesman for North Lanarkshire Council said: "We do not comment on personnel matters."
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