A pet deer, who would let children ride on his back, has been killed by trophy hunters, who hacked off his head and antlers.

Owners Manfred and Narelle Wagner were shocked to find their beloved red deer Karl lying headless on their property in Myrtleford, north-east Victoria, on Saturday afternoon.

Narelle and Manfred Wagner show off Karl's antlers from last year and hold a newly developed photograph of the deer. Credit:Mark Jesser, Border Mail

"I'm upset and gutted - it's like shooting your prized bull or horse," Mr Wagner said.

The 10-year-old stag's antlers would be worth up to $20,000.