My understanding of psionics in D&D is that it is usually tied to Intelligence.
Going by player classes, the UA Mystic class was Intelligence-based, and going by monsters, many of them who are capable of psionics appear to be Intelligence-based as well, such as the Mind Flayers (MM, p. 222):
Innate Spellcasting (Psionics). The mind flayer’s innate spellcasting ability is Intelligence …
However, I am aware that the Githzerai, both the playable race and the monsters, use Wisdom instead.
The playable race, from MToF (p. 96):
Githzerai Psionics. … Wisdom is your spellcasting ability for these spells.
And an example of one of the "monsters", a Githzerai Monk (MM, p. 161):
Innate Spellcasting (Psionics). The githzerai’s innate spellcasting ability is Wisdom …
Even the Githyanki (both playable race and monsters) use Intelligence, like most of the other psionic creatures in D&D. As far as I can tell, it’s just the Githzerai who are different in this regard.
I really want to ask "why do the Githzerai use Wisdom for psionics when everyone else uses Intelligence?", but that’s off-topic due to being a designer-reasons question. So instead, I will check my assumption, since I’m assuming that the Githzerai are the only ones who buck this trend, simply because I’ve not managed to find any further examples (i.e. "all swans are white").
Are there any other creatures who have psionic abilities (and the ability must be called out, either in lore or with the psionics tag, as being psionic; not just any old source of psychic damage or similar effects) that are not tied to Intelligence? If so, what creatures don’t follow this pattern, and what do they use instead of Intelligence (if anything)? Or is it literally just the Githzerai who buck this trend?
My understanding is based on D&D 5e, but I’d be interested in answers that consider psionics throughout all editions of D&D if that wouldn’t be asking too much (and if such a question would even make sense, given how the rules change between editions). If such a question would be too broad, or wouldn’t make sense, I’m happy to reduce the scope back to "just D&D 5e".