Bärendienst

Etymology
From. Compare 🇨🇬, 🇨🇬 and similar forms in other languages. From the French fable L’Ours et l’Amateur des jardins by Jean de La Fontaine, in which a tame bear wants to do his master a favour by hitting a fly that has sat down on the master's forehead, but hits it so hard that both the fly and the master are killed.

Noun

 * 1) disservice; mistaken favour, poisoned chalice something that is done with the intention to help, but turns out to be detrimental