The new councils will take over from Worcestershire County Council and the existing six district councils in 2028.
For Udall, that means his time on both the county council and Worcester City Council will end in two years’ time.
At Thursday’s meeting he said: “I’ve been a councillor in Worcestershire for 35 years – 30 years as a county councillor.
“Last September I received a Facebook Messenger post, [which contained a death threat] with a picture of my face superimposed on a 1960s American lynching,” he said.
“Only a couple of weeks ago I had a threat, and I won’t say the full wording, which included a threat to kill my dog, with a threat to put poisonous bacon through my letterbox.
“We all enter politics to serve, the opportunity to serve is all that we really ask,” he added.
The “nastiness and petty hostility” received by members was part of the reason he had decided to stand down, he told the meeting.
City council leader Lynn Denham said it was “almost impossible to believe” he may not be standing for re-election.
“Richard has lived and breathed the co-operative principles throughout his life – we need those values in local politics.”
Councillor Jabba Riaz, speaking at the meeting, said Local Government Association figures showed 72% of councillors had received abuse or intimidation in the past 12 months.
“I myself and my colleague have been subject to death threats, racism and petty name-calling,” he said.
“Officers, too, have been subjected to hostility. This is not normal and it must never become normal.”
