Most generations of a military animal mascot

The Mercian Regiment (formerly 95th Derbyshire Regiment of Foot) of the British Army has had a ram named "Derby" (most commonly ranked "Private" but occasionally higher) as its official mascot since 30 March 1858. The first sheep to take its name was found in Kohtah, India, by a Private Sullivan and then formally adopted by Lieutenant Colonel Raines; the latest recruit, Private Derby XXXII, was presented to the regiment in December 2017.

Initially "Derby" rams were recruited from whatever region the regiment was serving in, but since 1912 they have all been Swaledale rams provided by the Duke of Devonshire from the Chatsworth estate in Derbyshire, UK.

Private Derby XXX (2013-15) was promoted to Lance Corporal on 1 September 2015, making him the highest-ranking sheep at the time.

The longest-running animal mascot in the USA is Kolchak, a bolzoi or Russian wolfhound, who has represented the 27th Infantry Regiment (aka the "Wolfhounds") which formed in 1901; as of 2021, they have had 17 mascots by the name of Kolchak.