Here's one, as per this book -
Aindiram - said to be authored by Indra-deva himself.
Finally got a verse from the Sanskrit-Wiki-Website's page on the grammar Treatises (vyākaraṇagranthāḥ).
यथा च श्रूयन्तेऽत्र प्राचीनानि व्याकरणानि -
"ऐन्द्रं चान्द्रं काशकृत्स्नं कौमारं शाकटायनम् ।
चापिशलं शाकलं पाणिनीयकम् ॥"
Now listen about the nine ancient grammars viz. the "nava-vyākaraṇa"
Aindraṃ (authored by Indra-deva)
Cāndraṃ (authored by Candra-deva)
Kāśakṛtsnaṃ - (authored by ācārya Kāśakṛtsna) - mentioned by in the Mahābhāṣyam.
Kaumāraṃ - (authored by Śarvavarman via inspiration from Kumara Kārtikeya) - komāravyākaraṇa, an alternative name of the Kātantra Vyākaraṇa. Said to be slightly available in the Agni Purāṇa.
Śākaṭāyanam - (authored by ācārya Śākaṭāyana)
Sārasvataṃ - (said to be authored by an ancient grammarian named Narendra via inspiration from goddess Sarasvatī) - sārasvatavyākaraṇa
Āpiśalaṃ - (authored by ācārya Āpiśali) - also known as the āpiśalaṃ puṣkaraṇam.
Śākalaṃ - (authored by maharṣi Śākalya) - also called the Śākala Vyākaraṇa
Pāṇinīyakam - (authored by Pāṇinī ) - the famous Aṣṭādhyāyī sūtras.
The site traces these verses to Śrītattvanidhi - a 19th CE treatise on iconography and iconometry. I have supplemented some information on each grammar from the Wiki-site's Sanskrit (as much as I could understand), and from the Wisdomlib and other sources.
By the way, Hanumāna being referred to as the 'navavyākaraṇa-vettā' (and the future Brahmā) maybe found in the Uttara Kāṇḍa of the Vālmīki Rāmāyaṇa, Verse 7.36.48, as I discuss in this answer.