Fiendish Spirit

Large Fiend, Unaligned
Armor Class: 12 + the level of the spell (natural armor)
Hit Points: 50 (Demon only) or 40 (Devil only) or 60 (Yugoloth only) + 15 for each spell level above 6th
Speed: 40 ft., climb 40 ft. (demon only), fly 60 ft. (devil only)
STR
13 (+1)
DEX
16 (+3)
CON
15 (+2)
INT
10 (+0)
WIS
10 (+0)
CHA
16 (+3)


Source: Tasha’s Cauldron of Everything